osteoprotegerin and Inflammation

Periodontal disease is characterized by inflammation of the periodontal tissue and subsequent destruction of the alveolar bone. It is one of the most common infectious diseases in humans, being the leading cause of tooth loss in adults. Recently, it has been shown that the receptor activator of NF-κB ligand (RANKL) produced by osteoblasts and periodontal ligament fibroblasts critically contributes to the bone destruction caused by periodontal disease. Activation of the immune system plays an important role in the induction of RANKL during periodontal inflammation. Here we discuss the molecular mechanisms of periodontal bone destruction by focusing on the osteoimmune molecule RANKL.

Topics: Humans; Inflammation; Osteoclasts; Osteoprotegerin; Periodontal Diseases; Periodontal Ligament; Periodontitis; RANK Ligand

Osteoarthritis (OA) is a chronic degenerative disease afflicting millions globally. Despite the development of numerous pharmacological treatments for OA, a substantial unmet need for effective therapies persists. The RANK/RANKL signaling pathway has emerged as a promising therapeutic target for OA, owing to its pivotal role in regulating osteoclast differentiation and activity. In this comprehensive review, we aim to elucidate the relevant mechanisms of OA mediated by RANK/RANKL signaling, including bone remodeling, inflammation, cartilage degradation, osteophyte formation, and pain sensitization. Furthermore, we discuss and summarize the cutting-edge strategies targeting RANK/RANKL signaling for OA therapy, encompassing approaches such as gene-based interventions and biomaterials-aided pharmacotherapy. In addition, we highlight the prevailing challenges associated with pharmacological OA treatments and explore potential future directions, approached through a clinical-translational lens.

Topics: Bone Remodeling; Cartilage, Articular; Humans; Inflammation; Osteoarthritis; Osteoprotegerin; RANK Ligand; Signal Transduction

Abdominal aortic aneurysm (AAA) is one of the most dangerous cardiovascular diseases, occurring mainly in men over the age of 55 years. As it is asymptomatic, patients are diagnosed very late, usually when they suffer pain in the abdominal cavity. The late detection of AAA contributes to the high mortality rate. Many environmental, genetic, and molecular factors contribute to the development and subsequent rupture of AAA. Inflammation, apoptosis of smooth muscle cells, and degradation of the extracellular matrix in the AAA wall are believed to be the major molecular processes underlying AAA formation. Until now, no pharmacological treatment has been implemented to prevent the formation of AAA or to cure the disease. Therefore, it is important that patients are diagnosed at a very early stage of the disease. Biomarkers contribute to the assessment of the concentration level, which will help to determine the level and rate of AAA development. The potential biomarkers today include homocysteine, cathepsins, osteopontin, and osteoprotegerin. In this review, we describe the major aspects of molecular processes that take place in the aortic wall during AAA formation. In addition, biomarkers, the monitoring of which will contribute to the prompt diagnosis of AAA patients over the age of 55 years, are described.

Topics: Aorta, Abdominal; Aortic Aneurysm, Abdominal; Biomarkers; Cathepsins; Extracellular Matrix; Homocysteine; Humans; Inflammation; Male; Middle Aged; Osteopontin; Osteoprotegerin

Osteocytes comprise > 95% of the cellular component in bone tissue and produce a wide range of cytokines and cellular signaling molecules in response to mechanical stimuli. In this review, we aimed to summarize the molecular mechanisms involved in the osteocyte-mediated translation of mechanical stimuli to cellular signaling, and discuss their role in skeletal (bone) diseases and extra-skeletal (non-bone) clinical complications.

Topics: Adaptor Proteins, Signal Transducing; Adenosine Triphosphate; Bone and Bones; Bone Morphogenetic Proteins; Bone Neoplasms; Bone Remodeling; Calcium Signaling; Cytokines; Dinoprostone; Extracellular Vesicles; Humans; Inflammation; Insulin-Like Growth Factor I; Mechanotransduction, Cellular; Muscle, Skeletal; Nitric Oxide; Osteoblasts; Osteoclasts; Osteocytes; Osteoprotegerin; Parathyroid Hormone; RANK Ligand; Signal Transduction; Vascular Endothelial Growth Factor A; Wnt Signaling Pathway

Patients with chronic kidney disease (CKD) are at increased risk of osteoporosis and vascular calcification. Bone demineralization and vascular mineralization go often hand in hand in CKD, similar to as in the general population. This contradictory association is independent of aging and is commonly referred to as the "calcification paradox" or the bone-vascular axis. Various common risk factors and mechanisms have been identified. Alternatively, calcifying vessels may release circulating factors that affect bone metabolism, while bone disease may infer conditions that favor vascular calcification. The present review focuses on emerging concepts and major mechanisms involved in the bone-vascular axis in the setting of CKD. A better understanding of these concepts and mechanisms may identify therapeutics able to target and exert beneficial effects on bone and vasculature simultaneously.

Topics: Adaptor Proteins, Signal Transducing; Animals; Cardiovascular Diseases; Glucuronidase; Humans; Inflammation; Klotho Proteins; Osteoporosis; Osteoprotegerin; Parathyroid Hormone; Renal Insufficiency, Chronic; Signal Transduction; Vascular Calcification; Vitamin K

Apical periodontitis caused by root canal infection is the most frequent pathological lesion in the jaws, mainly manifested as periapical granulomas and cysts. Understanding of the formation and progression of apical periodontitis as well as the identification of inflammatory biomarkers can help increase the knowledge of pathogenic mechanisms, improve the diagnosis and provide support for different therapeutic strategies. The objective of the present article is to review inflammatory biomarkers such as cytokines, chemokines, inflammatory cells, neuropeptides, RANK/RANKL/OPG system and other inflammatory markers and to relate these systems to the development and progression of pathological conditions related to apical periodontitis.

Topics: Biomarkers; Humans; Inflammation; Osteoprotegerin; Periapical Periodontitis; Root Canal Therapy

The high prevalence of osteoporosis, observed in multiple sclerosis (MS) patients, has been attributed to reduced mobility and or the use of disease-modifying drugs. However, MS-impaired cardiovascular autonomic nervous system (ANS) function has the potential of reducing bone mass density (BMD) by altering the expression and/or function of the neuronal, systemic, and local mediators of bone remodeling. This review describes the complex regulation of bone homeostasis with a focus on MS, providing evidence that ANS dysfunction and low BMD are intertwined with MS inflammatory and neurodegenerative processes, and with other MS-related morbidities, including depression, fatigue, and migraine. Strategies for improving ANS function could reduce the prevalence of MS osteoporosis and slow the rate of MS progression, with a significant positive impact on patients' quality of life.

Topics: Adiponectin; Autonomic Nervous System; Bone Density; Bone Remodeling; Brain; Cardiovascular System; Depression; Endocannabinoids; Fatigue; Humans; Inflammation; Leptin; Migraine Disorders; Multiple Sclerosis; Nerve Degeneration; Neuropeptide Y; Osteocalcin; Osteopontin; Osteoporosis; Osteoprotegerin; Parathyroid Hormone; RANK Ligand; Serotonin; Vitamin D

The temporary anchorage devices (TADs) which include miniscrew implants (MSIs) have evolved as useful armamentarium in the management of severe malocclusions and assist in complex tooth movements. Although a multitude of factors is responsible for the primary and secondary stability of miniscrew implants, contemporary research highlights the importance of biological interface of MSI with bone and soft tissue in augmenting the success of implants. The inflammation and remodeling associated with MSI insertion or loading are reflected through biomarkers in peri-miniscrew implant crevicular fluid (PMICF) which is analogous to the gingival crevicular fluid. Analysis of biomarkers in PMICF provides indicators of inflammation at the implant site, osteoclast differentiation and activation, bone resorption activity and bone turnover. The PMICF for assessment of these biomarkers can be collected non-invasively via paper strips, periopaper or micro capillary pipettes and analysed by enzyme-linked immunosorbent assay (ELISA) or immunoassays. The markers and mediators of inflammation have been previously studied in relation to orthodontic tooth movement include interleukins (IL-1β, IL-2, IL-6 and IL-8), growth factors and other proteins like tumour necrosis factor (TNF-α), receptor activator of nuclear factor kappa-B ligand (RANKL), chondroitin sulphate (CS) and osteoprotegerin (OPG). Studies have indicated that successful and failed MSIs have different concentrations of biomarkers in PMICF. However, there is a lack of comprehensive information on this aspect of MSIs. Therefore, a detailed review was conducted on the subject.. A literature search revealed six relevant studies: two on IL-1β; one on IL-2, IL-6 and IL-8; one on TNF-α; one on CS; and one on RANKL/OPG ratio. One study showed an increase in IL-1β levels upon MSI loading, peak in 24 hours (h), followed by a decrease in 21 days to reach baseline in 300 days. A 6.87% decrease in IL-2 levels was seen before loading and a 5.97% increase post-loading. IL-8 showed a 6.31% increase after loading and IL-6 increased by 3.08% before MSI loading and 15.06% after loading. RANKL/OPG ratio increased in loaded compared to unloaded MSIs.. Cytokines (mainly ILs and TNF-α) and RANKL/OPG ratio showed alteration in PMICF levels upon loading of MSIs as direct or indirect anchorage.

Topics: Biomarkers; Bone Remodeling; Bone Screws; Chondroitin Sulfates; Cytokines; Gingival Crevicular Fluid; Humans; Inflammation; Interleukins; Orthodontic Anchorage Procedures; Osteoprotegerin; RANK Ligand; Tooth Movement Techniques; Tumor Necrosis Factor-alpha

Osteoporosis is a major cause of fractures and associated morbidity in the aged population. The pathogenesis of osteoporosis is multifactorial; whereas traditional pathophysiological concepts emphasize endocrine mechanisms, it has been recognized that also components of the immune system have a significant impact on bone. Since 2000, when the term 'osteoimmunology' was coined, novel insights into the role of inflammatory cytokines by influencing the fine-tuned balance between bone resorption and bone formation have helped to explain the occurrence of osteoporosis in conjunction with chronic inflammatory reactions. Moreover, the phenomenon of a low-grade, chronic, systemic inflammatory state associated with aging has been defined as 'inflamm-aging' by Claudio Franceschi and has been linked to age-related diseases such as osteoporosis. Given the tight anatomical and physiological coexistence of B cells and the bone-forming units in the bone marrow, a role of B cells in osteoimmunological interactions has long been suspected. Recent findings of B cells as active regulators of the RANK/RANKL/OPG axis, of altered RANKL/OPG production by B cells in HIV-associated bone loss or of a modulated expression of genes linked to B-cell biology in response to estrogen deficiency support this assumption. Furthermore, oxidative stress and the generation of advanced glycation end products have emerged as links between inflammation and bone destruction.

Topics: B-Lymphocytes; Cytidine Deaminase; Glycation End Products, Advanced; Humans; Inflammation; Osteoporosis; Osteoprotegerin; Oxidative Stress; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

The skeletal and immune systems share a multitude of regulatory molecules, including cytokines, receptors, signaling molecules, and signaling transducers, thereby mutually influencing each other. In recent years, several novel insights have been attained that have enhanced our current understanding of the detailed mechanisms of osteoimmunology. In orthodontic tooth movement, immune responses mediated by periodontal tissue under mechanical force induce the generation of inflammatory responses with consequent alveolar bone resorption, and many regulators are involved in this process. In this review, we take a closer look at the cellular/molecular mechanisms and signaling involved in osteoimmunology and at relevant research progress in the context of the field of orthodontic tooth movement.

Topics: Bone and Bones; Bone Remodeling; Cytokines; Humans; Immune System Phenomena; Inflammation; Osteoblasts; Osteoclasts; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction; Tooth Movement Techniques

Osteolysis and aseptic loosening currently contribute 75 % of implant failures. Furthermore, with over four million joint replacements projected to be performed in the United States annually, osteolysis and aseptic loosening may continue to pose a significant morbidity. This paper reviews the osteolysis cascade leading to osteoclast activation and bone resorption at the biochemical level. Additionally, the metal ion release mechanism from metallic implants is elucidated. Even though metal ions are not the predominating initiator of osteolysis, they do increase the concentration of key inflammatory cytokines that stimulate osteoclasts and prove to be a contributor to osteolysis and aseptic loosening. Osteolysis is a competitive mechanism among a number of biological reactions, which includes debris release, macrophage and osteoclast activation, an inflammatory response as well as metal ion release. Pharmacological therapy for component loosening has also been reviewed. A non-surgical treatment of osteolysis has not been found in the literature and thus may become an area of future research. Even though this research is warranted, comprehensively understanding the immune response to orthopedic implants and their metallic ions, and thus, creating improved prostheses appears to be the most cost-effective approach to decrease the morbidity related to osteolysis and to design implants with greater longevity. The ionic forms, cytokines, toxicity, gene expression, biological effects, and hypersensitivity responses of metallic elements from metal implants are summarized as well.

Topics: Cytokines; Humans; Inflammasomes; Inflammation; Ions; Joint Prosthesis; Macrophages; Metals; Osteoclasts; Osteolysis; Osteoprotegerin; Prosthesis Failure

A finely balanced relationship between bone resorption and bone formation is characteristic for a healthy bone metabolism. Osteoblasts are responsible for bone formation and osteoclasts for bone resorption. In general inflammatory and in particular chronic inflammatory processes influence osteoblast and osteoclast function directly or via indirect mechanisms. Bone metabolism can be influenced by the interaction of cytokines, hormones and growth factors with bone cells. A central factor involved in bone metabolism is the receptor activator of nuclear factor-κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system, which is influenced by different inflammatory processes. Usually, (chronic) inflammation results in increased bone loss. The molecular mechanisms and pathophysiological pathways of bone metabolism under the influence of inflammation are summarized in this review.

Topics: Bone and Bones; Bone Density; Bone Resorption; Humans; Inflammation; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

In this review the author summarizes the knowledge related to structural elements of bone tissue. The process of bone reorganisation and knowledge about the special feature of bone metabolism in human are also discussed. It is noted that due to the reorganisation, there is a complete renewal of bone tissue in every 10 years, and this renewal lasts throughout the life. However, there are life periods when osteoclast activity is low, e.g. in childhood and the second decade of life when the gain of bone mass may be as much as 40% of the final bone mass. Overactivity of osteoclasts occurs at age 60 years in men and somewhat earlier in women. Reorganization of bone tissue is an elementary requirement for the physiological functions (locomotion, hemopoiesis, immune functions). The RANK-RANKL-osteoprotegerin axis plays an important role in the regulation of bone metabolism. Bone mass is dependent on osteocytes; osteoblasts are building up while osteoclasts are reabsorbing bone tissue. In this process transcription factors, hormone-like substances and a large number of cytokines are involved. In addition, the inflammatory process within the bone tissue as well as the defending, reparative inflammation and specific immune response are of great importance in bone reorganisation. This is particularly valid for α2-macroglobulin and transforming growth factor, although the exact role in bone reorganization has not been fully explored. It can be concluded that the elements, which participate in bone reorganization and in defending inflammatory and specific immunological processes, are essentially identical. Therefore, the existence of an osteo-immunological complex system has emerged.. Az áttekintő munkában a szerző vázlatosan összefoglalja a csontszövet szerkezeti felépítésével kapcsolatos ismereteket. Ezt követően a csontújdonképződést, a humán csontrendszer különleges tulajdonságaival összefüggő adatokat tárgyalja. Rámutat arra, hogy a csontrendszeri újdonképződés következményeként dekádonként teljes mértékben kicserélődik a csontszövet állománya, és ez folyamatos az individuum élete végéig. Vannak olyan életszakaszok, amikor az osteoclast tevékenység háttérben marad, például gyerekkorban és a második életdekádban, amikor a csonttömeg körülbelül 40%-a adódik hozzá az addigi tömeghez. Az osteoclast tevékenység fölénye mutatkozik férfiakban a 60. életév táján, nőkben valamivel korábban. A csontújdonképződés elementáris szükséglet a csontszövet funkcióinak ellátásához (testtámasz, locomotio, folyamatos haemopoesis a szükséglethez mért tempóban, immunrendszeri hatás). A folyamat irányításában, lebonyolításában alapvető fontosságú a RANK-RANKL-osteoprotegerin tengely. A folyamat tempóját az osteocyta-tömeg, az osteoblastok irányítják, építik a csontszövetet, míg az osteoclastok lebontják azt. A folyamat szakadatlan irányításában transzkripciós molekulák, hormonszerű anyagok és cytokinek sokasága vesz részt közvetlenül. A csontszövetben zajló inflammatiós folyamat, az individuum más szervében zajló elhárító reparatív inflammatio és specifikus immunrendszeri tevékenység is befolyásolja a csontújdonképződést. Különösen érvényes ez a megállapítás az α2-macroglobulin és a transzformáló növekedési faktor vonatkozásában. Ezek pontos szerepköre még nem teljes mértékben feltárt. Megállapítható, hogy mind a kicserélődési, mind az elhárító inflammatiós és specifikus immunológiai folyamatokban részt vevő szerkezetek lényegében azonosak. Ennek alapján teljes joggal beszélhetünk osteoimmunológiai komplex rendszerről. Orv. Hetil., 2014, 155(40), 1575–1583.

Topics: alpha-Macroglobulins; Bone and Bones; Bone Density; Bone Remodeling; Bone Resorption; Humans; Inflammation; Osteoclasts; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Transforming Growth Factors

Chronic obstructive pulmonary disease (COPD) can no longer be considered as a disease affecting only the lungs. Increasing evidence supports the presence of a systemic inflammatory component which is thought to provide the link between COPD and the co-morbidities commonly associated with this disease. These include cardiovascular disorders, skeletal muscle dysfunction, diabetes, and osteoporosis. The majority of current therapies for COPD have been developed to improve airway obstruction or to target airway inflammation, leaving an unmet medical need with respect to the systemic inflammatory component of COPD and its extra-pulmonary manifestations. This review describes systemic biomarkers in COPD and their relationship with both the local lung and systemic manifestations of the disease. A summary is provided of the most promising biomarkers that have been investigated in COPD and its co-morbidities. Such biomarkers may be used to assess and manage the systemic effects of COPD, and may guide future development of novel therapeutic interventions to provide a more holistic approach to treating this multi-faceted disease.

Topics: Adiponectin; Aging; Airway Remodeling; Biomarkers; C-Reactive Protein; Cachexia; Cardiovascular Diseases; CD40 Ligand; Chemokines, CC; Cytokines; Desmosine; Fibrinogen; Humans; Inflammation; Intercellular Adhesion Molecule-1; Isodesmosine; Lung Neoplasms; Matrix Metalloproteinases; Natriuretic Peptide, Brain; Osteoprotegerin; Pulmonary Disease, Chronic Obstructive; Pulmonary Surfactant-Associated Protein D; Serum Amyloid A Protein; Severity of Illness Index; Telomere; Uteroglobin

Osteoprotegerin (OPG) is a 401 amino acid N-glycosylated protein, which is highly expressed in a large number of tissues. OPG mainly binds to two ligands, i.e. RANKL (receptor activator of nuclear factor κB ligand) and TRAIL (tumor necrosis factor- related apoptosis-inducing ligand). Upon binding to the former ligand, OPG inhibits the activation of osteoclasts and promotes apoptosis of osteoclasts, whereas the binding of OPG with TRAIL prevents apoptosis of tumor cells. There is now emerging evidence that OPG participates in the pathogenesis of atherosclerosis and cardiovascular diseases by amplifying the adverse effects of inflammation and several traditional risk factors such as hyperlipidemia, endothelial dysfunction, diabetes mellitus, and hypertension. Some epidemiological studies also showed a positive association between OPG levels and cardiovascular morbidity and mortality. The aim of this article is to provide an overview of the main biochemical, physiological, and pathological aspects of OPG biology in cardiovascular disease.

Topics: Aging; Aortic Diseases; Atherosclerosis; Blood Flow Velocity; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus; Endothelium, Vascular; Gene Expression; Humans; Inflammation; Lipids; Obesity; Osteoprotegerin; Polymorphism, Genetic; Prognosis; Vascular Calcification

The mortality of end-stage renal disease (ESRD) patients, including those receiving long-term peritoneal dialysis (PD), has remained unacceptably high owing to the prevalence of cardiovascular disease. It is well recognized that both traditional Framingham risk factors and kidney disease-related risk factors may contribute to the high prevalence of cardiovascular disease in these patients. Of the different risk factors, chronic inflammation frequently is observed in long-term PD patients. The causes of inflammation are usually complex and multifactorial, involving both dialysis-related and dialysis-unrelated factors. Inflammation is strongly associated with cardiovascular disease and malnutrition, and has been shown consistently to be a powerful predictor of mortality and adverse cardiovascular outcomes in PD patients. In this article we review the prevalence and potential causes of chronic inflammation in PD patients. More importantly, we provide emerging evidence that shows the serious consequences of chronic systemic inflammation in PD patients and the important contribution of inflammation to adverse clinical outcomes.

Topics: C-Reactive Protein; Cachexia; Calcinosis; Cardiomegaly; Chronic Disease; Heart Failure; Humans; Inflammation; Insulin Resistance; Kidney Failure, Chronic; Osteoprotegerin; Peritoneal Dialysis; Prevalence

Vitamin D has been shown to regulate musculoskeletal health by mediating calcium absorption and mineral homeostasis. Evidence has demonstrated that vitamin D deficiency may place subjects at risk for not only low mineral bone density/osteoporosis and osteopenia but also infectious and chronic inflammatory diseases. Studies have shown an association between alveolar bone density, osteoporosis and tooth loss and suggest that low bone mass may be a risk factor for periodontal disease. Several recent reports demonstrate a significant association between periodontal health and the intake of vitamin D. An emerging hypothesis is that vitamin D may be beneficial for oral health, not only for its direct effect on bone metabolism but also due to its ability to function as an anti-inflammatory agent and stimulate the production of anti-microbial peptides.

Topics: Antimicrobial Cationic Peptides; Bone Remodeling; Calcium; Humans; Immunity, Innate; Inflammation; Oral Health; Osteoblasts; Osteopontin; Osteoporosis; Osteoprotegerin; Periodontal Diseases; RANK Ligand; Rickets; Vitamin D

Recent studies have suggested that the dys-regulated progressive immune responses in some inflammatory conditions can lead to significantly increased osteoclasts (OC) frequency and activity associated with active bone destruction; termed inflammation-induced bone loss. Among the inflammatory infiltrates, monocytes/macrophages (Mo/MQ), T and B cells, have been well studied and documented as central players in osteoimmunological interactions (osteoimmunology: is an interdisciplinary field linking the immune and skeletal systems). We and others investigated the role(s) of dendritic cells (DC) during inflammation-induced osteoclastogenesis and bone loss. In addition to their innate effector functions, DC are potent professional antigen-presenting cells (APC) involved in triggering and orchestrating adaptive immunity, thereby implicated as potential osteo-immune players. Herein, bone remodeling and DC's biology including their development and functions are reviewed along with the contribution of DC at the crossroad of the osteo-immune interface during the process of inflammation-induced osteoclastogenesis. Furthermore, we provide a summary of recent progress, and discuss a proposed alternative mechanism underlying inflammation-induced bone loss. Understanding the cellular and molecular mechanisms regulating DC's roles in inflammation-induced osteoclastogenesis and bone loss might benefit future treatment approaches, especially if targeting DC can be translated into therapeutic strategies to ameliorate both tissue inflammation and bone destruction during disease progression associated with inflammatory bone diseases.

Topics: Adaptive Immunity; Animals; Bone Diseases; Bone Remodeling; Cytokines; Dendritic Cells; Humans; Immune System Phenomena; Inflammation; Osteoclasts; Osteoprotegerin; RANK Ligand; Signal Transduction; Toll-Like Receptors

Inflammation and bone loss are hallmarks of periodontal disease (PD). The question is how the former leads to the latter. Accumulated evidence demonstrates that PD involves bacterially derived factors and antigens that stimulate a local inflammatory reaction and activation of the innate immune system. Proinflammatory molecules and cytokine networks play essential roles in this process. Interleukin-1 and tumor necrosis factor-alpha seem to be primary molecules that, in turn, influence cells in the lesion. Antigen-stimulated lymphocytes (B and T cells) also seem to be important. Eventually, a cascade of events leads to osteoclastogenesis and subsequent bone loss via the receptor activator of nuclear factor-kappa B (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) axis. This axis and its regulation are not unique to PD but rather are critical for pathologic lesions involving chronic inflammation. Multiple lines of evidence in models of PD clearly indicate that increases in RANKL mRNA expression and protein production increase the RANKL/OPG ratio and stimulate the differentiation of macrophage precursor cells into osteoclasts. They also stimulate the maturation and survival of the osteoclast, leading to bone loss. OPG mRNA expression and protein production do not generally seem to be increased in the periodontitis lesion. Studies of RANKL and OPG transgenic and knockout animals provide further support for the involvement of these molecules in the tissue loss observed in PD. Ironically, periodontal practitioners have focused on the bacterial etiology of PD and believed that plaque removal was aimed at eliminating specific bacteria or bacterial complexes. However, it seems that the reduction of inflammation and attenuation of the host's immune reaction to the microbial plaque, eventually leading to a decrease in the ratio of RANKL/OPG and a decrease in associated bone loss, are the actual and desired outcomes of periodontal therapy. Future therapeutic options are likely to have regulation of the RANK-RANKL-OPG axis as their goal.

Topics: Alveolar Bone Loss; Antigens; Humans; Immunity, Innate; Inflammation; Inflammation Mediators; Osteoclasts; Osteoprotegerin; Periodontal Diseases; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

The mortality rate is extremely high in chronic kidney disease (CKD), primarily due to the high prevalence of cardiovascular disease (CVD) in this patient group. Apart from traditional Framingham risk factors, evidences suggest that nontraditional risk factors, such as inflammation, oxidative stress, endothelial dysfunction, and vascular calcification also contribute to this extremely high risk of CVD. Disturbance in the mineral metabolism, especially in the ions of Ca and PO4, are linked to enhanced calcification of blood vessels. Although the mechanism(s) of this enhanced calcification process are not fully understood, current knowledge suggests that a large number (and an imbalance between them) of circulating promoters and inhibitors of the calcification process, that is, fetuin-A (or alpha 2-Heremans-Schmid glycoprotein, AHSG), matrix-Gla protein (MGP), osteoprotegerin (OPG), osteopontin (OPN), bone morphogenetic proteins (BMPs), and inorganic pyrophosphate (PPi), are involved in the deterioration of vascular tissue. Thus, an imbalance in these factors may contribute to the high prevalence of vascular complications in CKD patients. Among these mediators, studies on fetuin-A deserve further attention as clinical studies consistently show that fetuin-A deficiency is associated with vascular calcification, all-cause and cardiovascular mortality in CKD patients. Both chronic inflammation and the uremic milieu per se may contribute to fetuin-A depletion, as well as specific mutations in the AHSG gene. Recent experimental and clinical studies also suggest an intriguing link between fetuin-A, insulin resistance, and the metabolic syndrome.

Topics: alpha-2-HS-Glycoprotein; Blood Proteins; Bone Morphogenetic Protein 7; Calcinosis; Calcium-Binding Proteins; Cardiovascular Diseases; Chronic Disease; Extracellular Matrix Proteins; Humans; Inflammation; Kidney Diseases; Matrix Gla Protein; Metabolic Syndrome; Osteopontin; Osteoprotegerin; Vascular Diseases

Similarities in the mechanisms of vascular calcification and the processes of bone and cartilage mineralization have come to light in recent years. Although formerly thought to be an inactive process of hydroxyapatite crystal precipitation, presently, vascular calcification is considered a regulated type of tissue mineralization. Moreover, different pathways of tissue mineralization are discussed. Pathological types of calcification are correlated with aging, metabolic disorders, chronic low-grade inflammation, and with genetic and acquired dysregulation of inorganic pyrophosphate (PPi) metabolism. This chapter focuses on recent developments in understanding the mechanisms of vascular calcification with special emphasis on the particular calcification pathway and the impact of deficient inhibition of calcification.

Topics: alpha-2-HS-Glycoprotein; Animals; Arteries; Blood Proteins; Calcinosis; Calcium-Binding Proteins; Extracellular Matrix Proteins; Humans; Inflammation; Matrix Gla Protein; Osteopontin; Osteoprotegerin; Phosphoric Diester Hydrolases; Pyrophosphatases; Vascular Diseases

Chronic diseases, such as periodontal disease (PD) and rheumatoid arthritis (RA), are characterized by a robust immune response resulting in unresolved inflammation. Inflammation is mediated by proinflammatory cytokines; recently, a novel subset of T-helper (Th) cells was identified that plays a crucial role in inflammation and autoimmune disease. This population secretes several proinflammatory cytokines, including the novel cytokine interleukin (IL)-17, and, hence, has been termed "Th17." Inflammatory cytokines are implicated in the progression of localized chronic infections, such as PD, and in serious systemic pathologies, such as diabetes, chronic obstructive pulmonary disease, and cardiovascular disease. IL-17 mediates inflammation through a receptor (IL-17R) composed of two subunits, IL-17RA and IL-17RC. Drugs that antagonize inflammatory cytokines are used therapeutically to downregulate immune-mediated pathology in conditions such as RA, although not all patients respond well to this approach. Therefore, identification of potential novel therapeutic targets, such as the IL-17 signaling complex, may be clinically relevant for mitigating inflammatory pathology. However, the manner in which such a therapeutic may influence the onset and progression of PD is poorly understood. Therapeutics that antagonize inflammatory cytokines ameliorate inflammation and bone loss and may have broader implications for individuals with systemic diseases in which inflammation and autoimmunity predominate.

Topics: Alveolar Bone Loss; Animals; Autoimmune Diseases; Autoimmunity; Humans; Inflammation; Interleukin-17; Mandibular Diseases; Maxillary Diseases; Mice; Osteoprotegerin; Periodontal Diseases; RANK Ligand; Receptors, Interleukin-17; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory

Focal bone loss around inflamed joints in patients with autoimmune disease, such as rheumatoid arthritis, remains a serious clinical problem. The recent elucidation of the RANK/RANK-ligand/OPG pathway and its role as the final effector of osteoclastogenesis and bone resorption has brought a tremendous understanding of the pathophysiology of inflammatory bone loss, and has heightened expectation of a novel intervention. Here, we review the etiology of inflammatory bone loss, the RANK/RANK-ligand/OPG pathway, and the clinical development of anti-RANK-ligand therapy.

Topics: Arthritis; Bone Diseases; Bone Resorption; Carrier Proteins; Glycoproteins; Humans; Inflammation; Membrane Glycoproteins; Models, Biological; Osteoclasts; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

In the recent past, it has become increasingly clear that extracellular calcium and phosphate homeostasis is a tightly regulated process. Since the physiological serum concentrations of calcium and phosphate are several orders of magnitude above their solubility product, mechanisms inhibiting precipitation must be operative to prevent extraosseous calcification. A number of local and systemic calcification inhibitors, including fetuin-A, matrix Gla protein, and osteoprotegerin, have been identified in recent years. Deficiency and dysregulation of such factors may contribute to morbidity and even mortality. Extraosseous calcifications occur with high prevalence in patients with end-stage renal disease. In particular, vascular manifestations are clearly associated with cardiovascular events and decreased survival. In addition to the well-established roles of hyperphosphatemia and an increased calcium x phosphate product, the biological and potential clinical roles of disturbances in calcification inhibition in uremia are discussed in this overview.

Topics: alpha-2-HS-Glycoprotein; Blood Proteins; Calcinosis; Calcium-Binding Proteins; Child; Extracellular Matrix Proteins; Humans; Inflammation; Matrix Gla Protein; Osteoprotegerin; Receptors, Tumor Necrosis Factor; Renal Insufficiency

The transcription factor nuclear factor (NF)-kappaB is well recognised as a pivotal player in osteoclastogenesis and inflammation induced bone loss. Here, the authors discuss their recent results, obtained using a genetic approach in mice, that indicate the importance of IKKbeta, and not IKKalpha, as a transducer of signals from receptor activator of NF-kappaB (RANK) to NF-kappaB. Ablation of IKKbeta results in lack of osteoclastogenesis and unresponsiveness of IKKbeta deficient mice to inflammation induced bone loss. In the need of a more effective therapy for the treatment of inflammatory diseases causing bone resorption, specific inhibition of IKKbeta represents a logical alternative strategy to the current therapies.

Topics: Animals; Bone Resorption; Glycoproteins; Humans; I-kappa B Kinase; Inflammation; Mice; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha

Rheumatoid arthritis, juvenile idiopathic arthritis, the seronegative spondyloarthropathies including psoriatic arthritis, and systemic lupus erythematosus are all examples of rheumatic diseases in which inflammation is associated with skeletal pathology. Although some of the mechanisms of skeletal remodeling are shared among these diseases, each disease has a unique impact on articular bone or on the axial or appendicular skeleton. Studies in human disease and in animal models of arthritis have identified the osteoclast as the predominant cell type mediating bone loss in arthritis. Many of the cytokines and growth factors implicated in the inflammatory processes in rheumatic diseases have also been demonstrated to impact osteoclast differentiation and function either directly, by acting on cells of the osteoclast-lineage, or indirectly, by acting on other cell types to modulate expression of the key osteoclastogenic factor receptor activator of nuclear factor (NF) kappaB ligand (RANKL) and/or its inhibitor osteoprotegerin (OPG). Further elucidation of the mechanisms responsible for inflammation-induced bone loss will potentially lead to the identification of novel therapeutic strategies for the prevention of bone loss in these diseases. In this review, we provide an overview of the cell types, inflammatory mediators, and mechanisms that are implicated in bone loss and new bone formation in inflammatory joint diseases.

Topics: Animals; Arthritis, Juvenile; Arthritis, Rheumatoid; Bone and Bones; Bone Remodeling; Bone Resorption; Carrier Proteins; Cytokines; Glycoproteins; Humans; Inflammation; Lupus Erythematosus, Systemic; Membrane Glycoproteins; Osteoclasts; Osteogenesis; Osteoprotegerin; Parathyroid Hormone-Related Protein; Prostaglandins; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Signal Transduction; Spondylarthropathies

Osteoprotegerin (OPG), a member of the TNF-receptor family expressed by osteoblasts, has documented effects on the regulation of bone metabolism. OPG inhibits bone resorption and binds with strong affinity to its ligand RANKL, thereby preventing RANKL from binding to its receptor RANK. This system is regulated by calcium-modifying hormones. OPG may also be pivotal in modulating the immune system. RANKL-deficient mice exhibit both severe immunological abnormalities and osteopetrosis, and activated T cells express RANKL mRNA. RANKL secretion by activated T cells may induce osteoclastogenesis via a mechanism enhanced by several cytokines (TNF-alpha, IL-1, and IL-17) that promote both inflammation and bone resorption. Conversely, this mechanism is inhibited by OPG, IL-4, and IL-10, which have antiinflammatory effects and inhibit osteoclast formation. Activated T cells in the rheumatoid synovium express RANKL. Synoviocytes can differentiate to osteoclast-like cells under specific conditions, particularly when they are cultured with M-CSF and RANKL. Thus, the bony erosions seen in RA may result from RANKL/RANK system activation by activated T cells. This raises the possibility that OPG therapy to block this mechanism might prove beneficial in patients with RA.

Topics: Animals; Arthritis, Rheumatoid; Glycoproteins; Humans; Inflammation; Mice; Osteoblasts; Osteolysis; Osteoprotegerin; Rats; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Tumor necrosis factor (TNF) and TNF receptor (TNFR) family proteins play important roles in many biological processes. Recently, the TNF-family molecule, RANKL (also called TRANCE, ODF, and OPGL), and its receptors, RANK and OPG, were found to be regulators of the development and activation of osteoclasts in bone remodeling. TNFalphaalso activates osteoclasts both by themselves and in synergy with RANKL. We used structure-based design to create peptidomimetics and organic therapeutics that inhibit osteoclastogenesis by inhibiting the interaction of ligands and receptors. Here we show for the first time that blocking TNFalpha by these small molecules effectively inhibited osteoclast formation in vitro. These mimetics can be used as a probe to understand the molecular basis of osteoclastogenesis and also as a platform to create useful therapeutic agent.

Topics: Carrier Proteins; Glycoproteins; Inflammation; Membrane Glycoproteins; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Osteoporosis is a major health concern in aging populations, where 54% of the U.S. population aged 50 and older have low bone mineral density (BMD). Increases in inflammation and oxidative stress play a major role in the development of osteoporosis. Men are at a greater risk of mortality due to osteoporosis-related fractures. Our earlier findings in rodent male and female models of osteoporosis, as well as postmenopausal women strongly suggest the efficacy of prunes (dried plum) in reducing inflammation and preventing/reversing bone loss. The objective of this study was to examine the effects of two doses of prunes, daily, on biomarkers of inflammation and bone metabolism in men with some degree of bone loss (BMD; t-score between -0.1 and -2.5 SD), for three months. Thirty-five men between the ages of 55 and 80 years were randomized into one of three groups: 100 g prunes, 50 g prunes, or control. Consumption of 100 g prunes led to a significant decrease in serum osteocalcin (

Topics: Aged; Aged, 80 and over; Biomarkers; Body Composition; Bone and Bones; Bone Density; Bone Remodeling; Exercise; Humans; Inflammation; Lumbar Vertebrae; Male; Middle Aged; Osteocalcin; Osteoporosis; Osteoporotic Fractures; Osteoprotegerin; Phytotherapy; Prunus domestica; RANK Ligand

To determine the association among bone mineral density (BMD), inflammatory markers, and alterations in fat and lean mass in untreated HIV-infected individuals.. Cross-sectional analysis of antiretroviral therapy-naive persons enrolled into a randomized clinical trial.. Dual-energy x-ray absorptiometry for BMD and lean and fat mass and a laboratory assessment were performed. Soluble biomarkers included adipocytokines (leptin and adiponectin), inflammatory markers (high-sensitivity C-reactive protein and interleukin 6), and markers related to bone metabolism [osteoprotegerin (OPG)], receptor activator of nuclear factor κB ligand. BMD at the lumbar spine, total hip, and femoral neck was expressed as a Z score (number of standard deviations away from age-, race-, and sex-matched reference population).. Three hundred thirty-one subjects had a median (Q1, Q3) age of 36 (28, 45) years, were 89% men, and 44% white. The prevalence of low BMD (Z score ≤ -2 at any of the 3 sites) was 10%. No associations were detected between Z scores and high-sensitivity C-reactive protein, interleukin 6, or receptor activator of nuclear factor κB ligand (P ≥ 0.1). In a linear model adjusting for age, gender, race, and total fat mass, lower lumbar spine Z scores were associated with lower total lean mass, higher serum adiponectin, and lower OPG. Results at the total hip or femoral neck were similar.. Among antiretroviral therapy-naive HIV-infected individuals, lower BMD was associated with lower lean mass, higher adiponectin, and lower OPG, but not HIV disease variables or any of the inflammatory markers. These findings may have implications for bone metabolism in untreated HIV, in which hypoadiponectinemia and higher OPG may mitigate bone loss.

Topics: Adiponectin; Adult; Body Composition; Body Mass Index; Bone Density; C-Reactive Protein; Cross-Sectional Studies; Female; HIV Infections; HIV-1; Humans; Inflammation; Interleukin-6; Leptin; Male; Metabolism, Inborn Errors; Middle Aged; Osteoprotegerin; RANK Ligand

To explore the potential role of Dickkopf-1 (DKK-1) in rheumatoid arthritis (RA) and to evaluate the effect of a tumor necrosis factor-α (TNF-α) inhibitor (infliximab) and an interleukin 1 receptor antagonist (IL-1Ra; anakinra) on DKK-1 secretion in patients with RA.. Serum samples were collected from 100 patients with RA, 100 patients with other rheumatic diseases (e.g., osteoarthritis and ankylosing spondylitis), and 40 healthy controls. DKK-1 and osteoprotegerin (OPG) levels in serum were detected by ELISA. Serum C-reactive protein (CRP) levels, erythrocyte sedimentation rates (ESR), rheumatoid factor (RF) titers, and anti-cyclic citrullinated peptide antibody were also measured in patients with RA.. The serum level of DKK-1 was significantly higher in patients with RA than in healthy controls and those with other rheumatic diseases (p < 0.01); the serum DKK-1 level was correlated with levels of CRP (r = 0.488, p = 0.003) and ESR (r = 0.458, p = 2.4 x 10(-4)) and the Sharp score of radiologic change (r = 0.449, p = 0.001) in RA. In contrast to the increasing level of OPG, DKK-1 was significantly decreased in RA patients treated with TNF-α inhibitor (p < 0.01). DKK-1 was significantly decreased in RA patients treated with IL-1Ra (p < 0.01).. DKK-1, as an important mediator, was correlated with bone erosion and inflammation in RA. The change of DKK-1 level may serve as a biomarker of disease activity and bone erosion.

Topics: Adult; Aged; Arthritis, Rheumatoid; Bone Resorption; C-Reactive Protein; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Interleukin 1 Receptor Antagonist Protein; Male; Middle Aged; Osteoprotegerin; Tumor Necrosis Factor-alpha; Young Adult

There is currently no cure for aseptic loosening (AL) of total joint replacement (TJR) except surgical revision. The purpose of this study was to determine whether oral EM could improve the periprosthetic tissue profiles and reduce serum cytokine production in AL patients who are candidates for surgical revision. We recruited 32 AL patients. AL patients were treated with either EM (600 mg/day, n=18) or placebo (n=14) daily, started one month before surgery and ending on the day of surgery. Blood samples were obtained before EM treatment and during surgery. Periprosthetic tissues and joint fluids were collected during surgery. Our results demonstrate that oral EM reduces the inflammation of periprosthetic tissues, as manifested by the reduction of the numbers of infiltrating cells, CD68+ macrophages, RANKL+ cells, and TRAP+ cells. Remarkable decreases of TNFalpha (9.6-fold), IL-1beta (21.2-fold), and RANKL (76-fold) gene transcripts were observed in periprosthetic tissues of patients treated with oral EM. Serum levels of both TNFalpha and (to a lesser extent) IL-1beta were significantly reduced following EM treatment (p<0.05). Our results suggest that EM represents a biological cure or prevention for those patients who might need repeated revision surgeries and/or show the early signs of progressive osteolysis after TJR.

Topics: Administration, Oral; Aged; Anti-Bacterial Agents; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Cytokines; Double-Blind Method; Enzyme-Linked Immunosorbent Assay; Erythromycin; Female; Gene Expression; Gene Expression Profiling; Humans; Immunohistochemistry; Inflammation; Joint Prosthesis; Leukocytes, Mononuclear; Male; Middle Aged; Osteolysis; Osteoprotegerin; Prosthesis Failure; RANK Ligand; Reoperation; Reverse Transcriptase Polymerase Chain Reaction

Calotropis procera latex protein (CpLP) is a popular anti-inflammatory and therefore we aimed to study its effects on inflammatory bone loss.. Male Wistar rats were subjected to a ligature of molars. Groups of rats received intraperitoneally CpLP (0.3 mg/kg, 1 mg/kg, or 3 mg/kg) or saline (0.9% NaCl) one hour before ligature and then daily up to 11 days, compared to naïve. Gingiva was evaluated by myeloperoxidase activity and interleukin-1 beta (IL-1β) expression by ELISA. Bone resorption was evaluated in the region between the cement-enamel junction and the alveolar bone crest. The histology considered alveolar bone resorption and cementum integrity, leukocyte infiltration, and attachment level, followed by immunohistochemistry bone markers between 1. The periodontitis significantly increased myeloperoxidase activity and the IL-1β level. The increased bone resorption was histologically corroborated by periodontal destruction, leukocyte influx, and attachment loss, as well as the increasing receptor activator of the nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) ratio, and Tartrate-resistant acid phosphatase (TRAP)+ cells when compared to naïve. CpLP significantly reduced myeloperoxidase activity, level of IL-1β, alveolar bone resorption, periodontal destruction, leukocyte influx, and attachment loss. The CpLp also reduced the RANKL/OPG ratio and TRAP+ cells, when compared with the saline group, and did not affect the systemic parameters.. CpLP exhibited a periodontal protective effect by reducing inflammation and restricting osteoclastic alveolar bone resorption in this rat model.

Topics: Alveolar Bone Loss; Alveolar Process; Animals; Antioxidants; Calotropis; Inflammation; Latex; Male; Osteoprotegerin; Peroxidase; RANK Ligand; Rats; Rats, Wistar

To investigate the functional changes of PDL fibroblasts in the presence of mechanical force, inflammation, or a combination of force and inflammation.. Inflammatory supernatants were prepared by inoculating human neutrophils with Porphyromonas gingivalis. Primary human PDL fibroblasts (PDLF), gingival fibroblasts (GFs), and osteoblasts (Saos2) were then exposed to the inflammatory supernatants. Orthodontic force on the PDLFs was simulated by centrifugation. Analyses included cell proliferation, cell viability, cell cycle, and collagen expression, as well as osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-Β ligand (RANKL) expression.. Mechanical force did not affect PDLF viability, but it increased the metabolic rate compared to resting cells. Force application shifted the PDLF cell cycle to the G0/G1 phase, arresting cell proliferation and leading to elevated collagen production, mild OPG level elevation, and robust RANKL level elevation. Including an inflammatory supernatant in the presence of force did not affect PDLF viability, proliferation, or cytokine expression. By contrast, the inflammatory supernatant increased RANKL expression in GFs, but not in Saos2 cells.. Applying mechanical force significantly affects PDLF function. Although inflammation had no effect on PDLF or Saos2 cells, it promoted RANKL expression in GF cells. Within the limitations of the in vitro model, the results suggest that periodontal inflammation and mechanical forces could affect bone catabolism through effects on different cell types, which may culminate in synergistic bone resorption.

Topics: Cells, Cultured; Collagen; Cytokines; Fibroblasts; Humans; Inflammation; Osteoclasts; Osteogenesis; Osteoprotegerin; Periodontal Ligament; RANK Ligand

Topics: Animals; Biomarkers; Humans; Inflammation; Lipopolysaccharides; Mice; Osteoprotegerin; Respiratory Distress Syndrome; Sepsis; Vascular Diseases

Cadmium (Cd) contamination in the environment is a major public health concern since it has been linked to osteoporosis and other bone deformities. Linarin is a flavonoid glycoside, and it can promote osteoblastogenesis. This research aimed to investigate the potential role of linarin against Cd-exposed bone deformations in mice model. In our research, male mice were randomly allocated into four groups: control, Cd-exposed, and Cd + linarin (20 and 40mg/kg/bw, respectively). Linarin prevented body weight loss, increased serum calcium (Ca) and phosphorus (P), and bone alkaline phosphatase (BAP) levels in Cd-exposed groups. Furthermore, linarin treatment at 20 and 40mg/kg/bw significantly decreased RANK and OPG, resulting in an increase in RANKL mRNA levels and protein distribution in the bone of Cd-exposed mice. In addition, the bone of Cd-exposed mice administered with linarin showed higher TRAP, NFATc1, MMP9, and RUNX2 mRNA levels and protein distribution. Linarin significantly decreased oxidative stress in Cd-exposed mice bone by decreasing MDA, a lipid peroxidation product. Moreover, linarin protects Cd-exposed mice antioxidant enzymes by increasing bone SOD, CAT, and GPx levels. Besides, linarin suppresses alterations in the inflammatory system, i.e., NF-κB p65/IKKβ, by reducing NF-κB p65, IKKβ, IL-6, and TNF-α in the bone of Cd-exposed animals. This study concluded that linarin has potential to cure osteoporosis in Cd-exposed mice by reducing oxidative stress and inflammation and modulating the RANK/RANKL/OPG pathway.

Topics: Animals; Cadmium; Glycosides; I-kappa B Kinase; Inflammation; Male; Mice; NF-kappa B; Osteoporosis; Osteoprotegerin; Oxidative Stress; RANK Ligand; RNA, Messenger; Signal Transduction

Osteoprotegerin (OPG), also known as osteoclastogenesis inhibitory factor or tumor necrosis factor receptor superfamily member 11B, is well known as a modulator of bone remodeling. The contribution of OPG to cardiovascular disease (CVD) has been suggested, but its molecular mechanism is complex and remains unclear. In the present study, Alves-Lopes et al. (Clin. Sci. (Lond.) (2021) 135(20): https://doi.org/10.1042/CS20210643) reported the critical role of syndecan-1 (SDC-1, also known as CD138), a surface protein part of the endothelial glycocalyx, in OPG-induced vascular dysfunction. The authors found that in endothelial cells (ECs), through SDC-1, OPG increased eNOS Thr495 phosphorylation, thereby inhibiting eNOS activity. Furthermore, the OPG-SDC-1 interaction increased reactive oxygen species (ROS) production through NOX1/4 activation. Both the reduced eNOS activity and induced ROS production inhibited NO production and impaired EC function. In vascular smooth muscle cells (VSMCs), the OPG-SDC-1 interaction increased ROS production through NOX1/4 activation, subsequently increased MLC phosphorylation-mediated Rho kinase-MYPT1 regulation, leading to increased vascular contraction. Ultilizing wire myography and mechanistic studies, the authors nicely provide the evidence that SDC-1 plays a crucial role in OPG-induced vascular dysfunction. As we mentioned above, the molecular mechanism and roles of OPG in cardiovascular system are complex and somewhat confusing. In this commentary, we briefly summarize the OPG-mediated signaling pathways in cardiovascular system.

Topics: Endothelial Cells; Humans; Inflammation; Osteoprotegerin; Oxidative Stress; Reactive Oxygen Species

High serum levels of osteoprotegerin (OPG) are found in patients with obesity, type 2 diabetes, sepsis, or septic shock and are associated with a high mortality rate in stroke. The primary known function of OPG is to bind to the receptor activator of NF-

Topics: Diabetes Mellitus, Type 2; Humans; Inflammation; Lipopolysaccharides; Macrophages; Obesity; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; TNF Receptor-Associated Factor 6; Toll-Like Receptor 4

The understanding of the biological mechanisms involved in root resorption in deciduous teeth is important to the future development of preventive measures and treatments of this condition. The aim of the present study was to compare the expression and immunostaining of iNOS, MMP-9, OPG and RANKL in the periodontal ligament (PDL) of deciduous teeth with physiologic root resorption (GI), inflammatory pathological root resorption (GII) and permanent teeth (GIII), the negative control. Teeth in GI (n = 10), GII (n = 10) and (GIII) (n = 10) were submitted to immunohistochemical analysis to determine the expression of iNOS, MMP-9, OPG, and RANKL. The immunostaining was analysed by optical density. Statistical analysis included one-way ANOVA, followed by Student-Newman-Keuls post hoc test (p < 0.05). The results showed that iNOS, MMP-9 and RANKL expression in the PDL was higher in GII compared to GI and GIII (p < 0.05). Moreover, RANKL expression was higher in GI compared to GIII (p < 0.001), while OPG immunolabelling was lower in GII compared to GI and GIII (p < 0.001). The PDL of deciduous teeth bearing inflammatory processed exhibited upregulation of resorption-associated factors as well as enzymes related to tissue degradation which, in turn explains the exacerbation and greater susceptibility of those teeth to root resorption process.

Topics: Humans; Inflammation; Matrix Metalloproteinase 9; Osteoprotegerin; Periodontal Ligament; RANK Ligand; Root Resorption; Tooth, Deciduous

Epidemiology and pathogenesis of cardiovascular diseases (CVD) and osteoporosis are strikingly overlapping. This study presents matrix metalloproteinase-9 (MMP-9), as a simple molecular link more consistently associated with the pathophysiology of both osteoporosis and CVD risk factors. 40 adult female rats were randomly distributed into 4 groups [control sham-operated, untreated osteoporosis, carvedilol-treated osteoporosis and alendronate-treated osteoporosis]. After 8 weeks, blood samples were collected to estimate Lipid profile (Total cholesterol, HDL, Triglycerides), inflammatory markers (IL-6, TNF alpha, CRP and NO), and Bone turnover markers (BTM) (Alkaline phosphatase, osteocalcin and pyridinoline). The tibias were dissected to estimate MMP-9 and NF-kB gene expression, OPG, RANKL levels and for histological examination. Induction of osteoporosis resulted in a significant elevation in BTM, inflammatory markers and dyslipidemia. MMP-9 was significantly elevated and positively correlated with BTM, inflammation and dyslipidemia markers. Carvedilol and alendronate exerted a bone preservative role and attenuated dyslipidaemia and inflammation in accordance with their respective effect on MMP-9.

Topics: Alkaline Phosphatase; Amino Acids; Animals; Bone Remodeling; Cardiovascular Diseases; Cholesterol; Cortical Bone; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Inflammation; Lipoproteins, HDL; Matrix Metalloproteinase 9; NF-kappa B; Osteocalcin; Osteoporosis, Postmenopausal; Osteoprotegerin; Ovariectomy; RANK Ligand; Rats; Risk Factors; Tibia; Triglycerides

MicroRNA-146a (miR-146a) is a regulator of inflammatory response. Periodontitis is a disease with immune pathophysiology of the periodontium in which the inflammation results in the destruction of the soft tissues and alveolar bone. Therefore, the aim of this study was to investigate the expressions of miR-146a, OPG, and RANKL in diseased and healthy periodontal tissues to understand whether miR-146a expression level may associate with OPG and RANKL mRNA levels and OPG/RANKL ratio after non-surgical periodontal treatment.. The levels of miR-146a, RANKL, and OPG in gingival tissues from patients with generalized periodontitis stages II and III and grades A and B (n = 15, group A), patients with generalized periodontitis stages III and IV and grade C (n = 15, group B), and healthy individuals (n = 10) were determined by real-time PCR. The associations of miR-146a expression with OPG and RANKL levels were evaluated.. The levels of miR-146a in two subgroups within periodontitis patients were significantly higher than healthy subjects (P < 0.0001). MiR-146a showed the increased level in group A of patients compared with group B (P < 0.05). Clinical parameters such as probing depth (PD) and clinical attachment loss (CAL) were significantly higher in patients than control group (P < 0.05). The levels of OPG and RANKL were increased in patients compared with healthy subjects, although the elevated levels were not statistically significant. MiR-146a was not associated with OPG and RANKL levels and OPG/RANKL ratio.. The results of this study failed to show the associations of miR-146a level with OPG and RANKL levels and OPG/RANKL ratio in periodontitis after non-surgical periodontal treatment.

Topics: Gingiva; Humans; Inflammation; MicroRNAs; Osteoprotegerin; Periodontitis; RANK Ligand

Osteoprotegerin (OPG) belongs to the tumour necrosis factor superfamily and is known to accelerate endothelial dysfunction and vascular calcification. OPG concentrations are elevated in patients with chronic kidney disease. The aim of this study was to investigate the association between OPG levels and frequent complications of chronic kidney disease (CKD) such as anaemia, protein energy wasting (PEW), inflammation, overhydration, hyperglycaemia and hypertension.. One hundred non-dialysis-dependent men with CKD stage 3-5 were included in the study. Bioimpedance spectroscopy (BIS) was used to measure overhydration, fat amount and lean body mass. We also measured the serum concentrations of haemoglobin, albumin, total cholesterol, C-reactive protein (CRP), fibrinogen and glycated haemoglobin (HgbA1c), as well as blood pressure.. We observed a significant, positive correlation between OPG and age, serum creatinine, CRP, fibrinogen, HgbA1c concentrations, systolic blood pressure and overhydration. Negative correlations were observed between OPG and glomerular filtration rate (eGFR), serum albumin concentrations and serum haemoglobin level. Logistic regression models revealed that OPG is an independent marker of metabolic complications such as anaemia, PEW, inflammation and poor renal prognosis (including overhydration, uncontrolled diabetes and hypertension) in the studied population.. Our results suggest that OPG can be an independent marker of PEW, inflammation and vascular metabolic disturbances in patients with chronic kidney disease.

Topics: Aged; Anemia; Biomarkers; Humans; Inflammation; Logistic Models; Male; Middle Aged; Osteoprotegerin; Prognosis; Renal Dialysis; Renal Insufficiency, Chronic

The effect of implantable Zoledronate-PLGA microcapsules (PLGA-ZOL) in periodontitis remains unclear. In this study, we aimed to explore the potential role of PLGA-ZOL in protecting periodontitis and elucidate the underlying mechanism. A rat model of periodontitis was established by ligation the mandibular first molars, then PLGA-ZOL was implanted. The healing volume was scanned by cone-beam computed tomography. Cytokine levels in the gingival tissues were determined by ELISA and RT-PCR. Oxidative stress was indicated by detecting superoxide dismutase concentration and catalase activity. After periodontitis model was successfully established in rats, PLGA-ZOL treatment significantly attenuated alveolar bone loss, as indicated by the increased total healing volume, bone volume/tissue volume and osteoprotegerin level, as well as decreased sRANKL level. PLGA-ZOL treatment also suppressed the inflammatory activities by inhibiting pro-inflammatory cytokine production (TNF-α, IL-1β) but increasing anti-inflammatory cytokine secretion (IL-10). Furthermore, PLGA-ZOL was found to ameliorate oxidative stress in gingival tissues. In conclusion, PLGA-ZOL microcapsules ameliorate alveolar bone loss, gingival inflammation and oxidative stress in an experimental rat model of periodontitis.

Topics: Alveolar Bone Loss; Animals; Antioxidants; Capsules; Catalase; Cytokines; Disease Models, Animal; Gingiva; Humans; Inflammation; Osteoprotegerin; Oxidative Stress; Polylactic Acid-Polyglycolic Acid Copolymer; Prosthesis Implantation; Rats; Superoxide Dismutase; Zoledronic Acid

Lamiophlomisrotata (Benth.) Kudo. has been used to treat trauma bleeding, rheumatism, yellow water disease in traditional Chinese medicine.. The aim of this work was to evaluate the anti-rheumatoid arthritis (RA) activities and underlying mechanisms of the total iridoid glucosides (TIG) from Lamiophlomisrotata (Benth.) Kudo.. The chemical constituents of TIG was analyzed by high-performance liquid chromatography (HPLC) with seven reference compounds (penstemonoside, chlorotuberside, shanzhiside methyl ester, phloyoside, 7-epliamalbide, phlorigidoside C and lamalbide). The anti-rheumatoid arthritis effects of TIG were investigated by arthritis indexes and paw swelling degrees, as well as histopathological and Micro-CT analysis in adjuvant-induced arthritis (AIA) rats. The impacts of TIG on the level of inflammatory cytokines (IL-1β, TNF-α, IL-6, IFN-γ, IL-17 and IL-10), and the regulation of OPG/RANKL/NF-κB pathways were determined by the ELISA and western blot, respectively.. TIG significantly reduced the arthritis indexes and paws swelling in AIA rats, attenuated the inflammation and bone destruction in joint tissues, reduced the generation of pro-inflammatory cytokines IL-1β, TNF-α, IL-6, IFN-γ and IL-17, as well as increased the generation of anti-inflammatory cytokine IL-10 in serum. Moreover, TIG markedly inhibited the expression of p-IKK-α, p-IκB and p-p65, and decreased the ratio of OPG/RANKL in the synovial tissues.. TIG possessed significant anti-RA activities on adjuvant-induced arthritis, which might be ascribed to the regulation of inflammatory cytokines IL-1β, TNF-α, IL-6, IFN-γ IL-17 and IL-10, as well as inhibition of OPG/RANKL/NF-κB signaling pathways.

Topics: Animals; Antirheumatic Agents; Arthritis, Experimental; Arthritis, Rheumatoid; Cytokines; Female; Inflammation; Iridoid Glycosides; Lamiaceae; NF-kappa B; Osteoprotegerin; RANK Ligand; Rats; Rats, Sprague-Dawley; Signal Transduction

M. pumilum has been claimed to protect the bone against the adverse effect of estrogen deficiency. Additionally, it also exhibits anti-diabetic activity. In view of these, this study aims to identify the mechanisms underlying the bone protective effect of M. pumilum in the presence of both estrogen deficiency and diabetes mellitus (DM).. Ovariectomized, diabetic female rats were given M. pumilum leave aqueous extract (MPLA) (50 and 100 mg/kg/day), estrogen, glibenclamide and estrogen plus glibenclamide for 28 consecutive days. At the end of the treatment, fasting blood glucose (FBG), serum insulin, Ca. MPLA helps to overcome the adverse effect of estrogen deficiency and DM on the bone and thus this herb could potentially be used for the treatment and prevention of osteoporosis in postmenopausal women with diabetes.

Topics: Animals; Bone and Bones; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Estrogens; Female; Inflammation; Osteoprotegerin; Ovariectomy; Oxidative Stress; Plant Extracts; Plant Leaves; Primulaceae; RANK Ligand; Rats; Rats, Sprague-Dawley; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction

Osteoprotegerin and osteopontin have recently emerged as key factors in both vascular remodelling and atherosclerosis progression. Interleukin-6 (IL-6) is an inflammatory cytokine with a key role in atherosclerosis. The relationship of osteoprotegerin, osteopontin, and IL-6 serum levels with endothelial function and arterial stiffness was evaluated in patients with coronary artery disease (CAD).. We enrolled 219 patients with stable CAD and 112 control subjects. Osteoprotegerin, osteopontin and IL-6 serum levels were measured using an ELISA assay. Endothelial function was evaluated by flow-mediated dilation (FMD) in the brachial artery and carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness.. There was no significant difference between control subjects and CAD patients according to age and sex. Compared with control subjects, CAD patients had significantly impaired FMD (p<0.001) and increased PWV (p=0.009). CAD patients also had significantly higher levels of osteoprotegerin (p<0.001), osteopontin (p<0.001) and IL-6 (p=0.03), compared with control subjects. Moreover, IL-6 levels were correlated with osteoprotegerin (r=0.17, p=0.01) and osteopontin (r=0.30, p<0.001) levels. FMD was correlated with osteoprotegerin levels independent of possible confounders [b coefficient= - 0.79, 95% CI (-1.54, -0.05), p=0.04].. CAD patients have increased osteoprotegerin, osteopontin and IL-6 levels. Moreover, there is a consistent association between osteoprotegerin and osteopontin serum levels, vascular function and inflammation in CAD patients. These findings suggest another possible mechanism linking osteoprotegerin and osteopontin serum levels with CAD progression through arterial wall stiffening and inflammation.

Topics: Aged; Biomarkers; Case-Control Studies; Coronary Artery Disease; Female; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Osteopontin; Osteoprotegerin; Vascular Stiffness; Vasodilation

Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis. We investigated two main types of Tregs, the CD4+FOXP3+ and IL-10+ Tr1, in pediatric subjects with inflammatory bowel disease (IBD) both at diagnosis and after the clinical remission.. Peripheral blood Tregs were analyzed in 16 children with Crohn's disease (CD), 19 with ulcerative colitis (UC), and 14 healthy controls (HC). Two cocktails of fluoresceinated antibodies were used to discriminate between CD4+FOXP3+ and Tr1.. We observed in both CD and UC groups a higher frequency of Tr1 at diagnosis compared to controls, which decreased at follow-up compared to diagnosis, in particular in UC. Similarly, in UC patients the percentage of CD4+FOXP3+ Tregs markedly decreased at follow-up compared to the same patients at diagnosis and compared to HC. The expression of CTLA-4 in CD4+FOXP3+ Tregs increased in both groups at clinical remission.. This study shows that IBD children present at diagnosis an increased frequency of circulating Tregs, probably as a compensative reaction to tissue inflammation. During the clinical remission, the Treg frequency diminishes, and concomitantly, their activation status increases. Notwithstanding, the high Treg density at diagnosis is not sufficient to counteract the inflammation in the childhood IBD.

Topics: Adolescent; CD4-Positive T-Lymphocytes; Child; Female; Forkhead Transcription Factors; Humans; Inflammation; Inflammatory Bowel Diseases; Interleukin-10; Leukocytes, Mononuclear; Male; Osteoprotegerin; Remission Induction; T-Lymphocytes, Regulatory

To investigate the influence of chronic stress and adrenergic blockade in a rat model of apical periodontitis.. Thirty-two Wistar rats were submitted to an animal model of periapical lesion and randomly divided into 4 groups (n = 8): no stress (NS); stress + saline solution (SS); stress + β-adrenergic blocker (Sβ); stress + α-adrenergic blocker (Sα). The SS, Sβ and Sα groups were submitted to an animal model of chronic stress for 28 days and received daily injections of saline solution, propranolol (β adrenergic blocker) and phentolamine (α adrenergic blocker), respectively. After 28 days the animals were euthanized and the following analyses were carried out: a) serum corticosterone levels through Radioimmunoassay; b) measurement of serum levels of IL-1B, IL-6, IL-10 and IL-17 by enzyme-linked immunosorbent assay (ELISA); c) volume of periapical bone resorption by micro-computed tomography; d) histomorphometric analysis by staining with hematoxylin and eosin; e) expression of β-AR, α-AR, receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) by immunohistochemistry; f) tartrate-resistant acid phosphatase (TRAP) staining; g) ex-vivo cytokine release followed by the stimulation with LPS in superfusion system, by ELISA.. SS group displayed significantly higher corticosterone levels than NS group (non-stressed). Higher IL-1β serum level was observed in the NS group (p < .05); compared to all stressed groups. Other cytokines were present in similar amounts in the serum of all groups. All groups presented similar periapical lesions. All groups presented moderate inflammatory infiltrate, without statistically significant differences between them. No differences were observed regarding β-AR, α-AR, Rank-L and OPG expression. The number of TRAP-positive cells was significantly decreased in the groups that received daily injections of adrenergic blockers. The IL-1β release followed LPS stimulation was significantly suppressed when the superfusion media contained propranolol (p < .05). Perfusion containing phentolamine induced a greater release of IL-10. TGF-β was significantly suppressed by phentolamine perfusion in the NS group (p < .05).. Chronic stress can significantly change the inflammatory cytokines release. Rank-L/OPG system and periapical lesion volume were not affected following the current method applied. The administration of adrenergic blockers was not able to modulate the inflammatory response but presented effectivity in reducing the number of osteoclasts in the periapical region.

Topics: Adrenergic Agents; Animals; Bone Resorption; Inflammation; Osteoprotegerin; Oxidative Stress; Periapical Periodontitis; RANK Ligand; Rats; Rats, Wistar; Receptors, Adrenergic; Stress, Physiological; X-Ray Microtomography

To investigate the regulation of inflammatory and osteoclastogenic signaling by 5-lipoxygenase (5-LO) in apical periodontitis induced by oral contamination of dental root canals in mice.. Apical periodontitis was induced in 5-lipoxygenase enzyme knockout (129-Alox5. Oral contamination of dental root canals induced recruitment of neutrophils and osteoclasts to the periodontal ligament, resulting in bone resorption. Absence of 5-LO did not impair neutrophil recruitment while osteoclastic formation was increased. Nonetheless, early bone resorption progressed similarly to lesions in wild-type animals. Interestingly, in the absence of 5-LO, the synthesis of mRNAs for cytokines, chemokines, and their receptors was significantly reduced while that of regulators of osteoclastogenesis (RANK, RANKL, and OPG) was increased in comparison with the corresponding levels in wild-type animals.. The 5-LO pathway plays a role in the stimulation of inflammatory mediator synthesis and inhibition of osteoclastogenesis in apical periodontitis in mice. However, the paradoxical inflammatory-osteoclastogenic signaling did not impair inflammatory cell recruitment and bone resorption during early development of the disease.

Topics: Animals; Arachidonate 5-Lipoxygenase; Bone Resorption; Inflammation; Mice; Mice, Knockout; Osteoclasts; Osteogenesis; Osteoprotegerin; Periapical Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Periodontitis is the chronic destructive disease of the periodontium, which causes severe inflammation in the tissues. Cinnamic acid as an unsaturated carboxylic acid might prevent inflammation and periodontal destruction. The present study aimed to evaluate the effects of cinnamic acid in two different forms as free cinnamic acid and cinnamic acid liposome on experimental periodontitis in Wistar rats.. Thirty-two female rats were used in the present study. Four main groups were created as follows: C: control group; P: periodontitis group; C-P: free cinnamic acid-administered periodontitis group; and CL-P: cinnamic acid liposome applied group. Periodontitis was induced via ligating 4-0 silk sutures around lower first molar teeth on both right and left mandibles. The study duration was 30 days, and the ligatures were removed from half of the rats in the periodontitis-induced groups. The other half carried the ligatures throughout 30 days, and all rats were euthanized at 30th day. Mandibles were removed and evaluated via stereomicroscope and underwent histological procedures. Inflammatory cell counts, osteoblast, and osteoclast cell counts were determined in hematoxylin-eosin-stained slides, and peroxisome proliferator-activated receptor (PPAR)-γ, cyclooxygenase (COX)-2, receptor activator of nuclear factor κ-B (RANKL), and osteoprotegerin (OPG) expressions were evaluated by immunohistochemistry.. Control group had the lowest bone loss, and periodontitis group which kept ligatures had the highest bone loss compared to the other groups. Ligature removal provided significant improvement in bone measurements. Cinnamic acid groups also showed lower bone loss compared to the periodontitis group. The inflammatory cell and osteoclast counts were also higher in the periodontitis group, and both applications of cinnamic acid decreased these values. Osteoblast cells were the lowest in the periodontitis group, and cinnamic acid increased these counts. PPAR-γ and COX-2 levels were higher in the periodontitis group, and cinnamic acid decreased these levels but not to a significant level except for the cinnamic acid liposome ligature removal group, which had significantly lower values in the PPAR-γ and COX-2. OPG levels were lower in the periodontitis group compared to the other groups. Cinnamic acid significantly decreased RANKL and increased OPG levels.. Periodontitis caused increased inflammation and bone destruction accompanied by increased PPAR-γ, COX-2, and RANKL levels and osteoclast counts. Cinnamic acid decreased osteoclast counts and inflammation and increased osteoblast counts and OPG expression in the present animal model of periodontitis.

Topics: Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; Cinnamates; Female; Inflammation; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar

To evaluate the relationship between systemic administration of probiotics and inflammation/resorption processes associated with apical periodontitis (AP) in a rat model.. Twenty-four male Wistar rats were used. AP was induced in the mandibular left/right first molars. The animals were arranged into three groups: Control, Lactobacillus rhamnosus and L. acidophilus. Probiotics were orally administered via gavage (10. There was no significant difference in the calcium and phosphorus levels in plasma amongst the groups (P > 0.05). The level of alkaline phosphatase was significantly higher in the groups that consumed probiotics (P < 0.05). A significantly lower volume of bone resorption was observed in groups that consumed probiotics (P < 0.05). The inflammatory infiltrates and the immunolabelling for RANKL and TRAP were significantly lower in probiotic groups when compared to the control (P < 0.05). Also, the OPG was significantly more immunolabelled in the L. acidophilus group than in the L. rhamnosus and control groups (P < 0.05).. Probiotic supplementation through gavage (L. rhamnosus and L. acidophilus) had a significant effect on the reduction of inflammation and bone resorption in apical periodontitis development in rats.

Topics: Animals; Bone Resorption; Inflammation; Male; Osteoprotegerin; Periapical Periodontitis; Probiotics; RANK Ligand; Rats; Rats, Wistar; X-Ray Microtomography

Aseptic loosening caused by periprosthetic osteolysis (PPO) is the main reason for the primary artificial joint replacement. Inhibition of inflammatory osteolysis has become the main target of drug therapy for prosthesis loosening. MiR-106b is a newly discovered miRNA that plays an important role in tumour biology, inflammation and the regulation of bone mass. In this study, we analysed the in vivo effect of miR-106b on wear debris-induced PPO. A rat implant loosening model was established. The rats were then administrated a lentivirus-mediated miR-106b inhibitor, miR-106b mimics or an equivalent volume of PBS by tail vein injection. The expression levels of miR-106b were analysed by real-time PCR. Morphological changes in the distal femurs were assessed via micro-CT and histopathological analysis, and cytokine expression levels were examined via immunohistochemical staining and ELISA. The results showed that treatment with the miR-106b inhibitor markedly suppressed the expression of miR-106b in distal femur and alleviated titanium particle-induced osteolysis and bone loss. Moreover, the miR-106b inhibitor decreased TRAP-positive cell numbers and suppressed osteoclast formation, in addition to promoting the activity of osteoblasts and increasing bone formation. MiR-106b inhibition also significantly regulated macrophage polarization and decreased the inflammatory response as compared to the control group. Furthermore, miR-106b inhibition blocked the activation of the PTEN/PI3K/AKT and NF-κB signalling pathways. Our findings indicated that miR-106b inhibition suppresses wear particles-induced osteolysis and bone destruction and thus may serve as a potential therapy for PPO and aseptic loosening.

Topics: Animals; Bone and Bones; Bone Resorption; Cell Count; Cell Polarity; Cytokines; Inflammation; Kidney; Liver; Macrophages; Male; MicroRNAs; NF-kappa B; Osteoclasts; Osteogenesis; Osteolysis; Osteoprotegerin; Phosphatidylinositol 3-Kinases; Prostheses and Implants; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; RANK Ligand; Rats, Sprague-Dawley; Signal Transduction; Titanium

Obesity and latent inflammation can give rise to insulin resistance and type 2 diabetes. Here we established an insulin resistance model of osteoblasts to explore the restoration effect of anti-inflammatory interleukin-4 (IL-4) on insulin sensitivity and its mechanism. We found that IL-4 inhibited cell proliferation in a concentration- and time-dependent manner. Insulation resistance significantly reduced the phosphorylation levels of the insulin receptor substrate 1 (IRS1; Tyr612), Akt (Ser473), and AS160 (Ser318) proteins. The addition of IL-4 to the insulin resistance model led to a dose-dependent stimulation of the phosphorylation of IRS1, Akt, and AS160. IL-4 fully restored the activation of the insulin cascade in insulin-resistant cells at the concentration of 50 ng/ml. Additionally, IL-4 promoted the expression of IRS1 in a time-dependent manner. We conjecture that IL-4 restores insulin sensitivity in osteoblasts by upregulating the expression of IRS1. It was also found that IL-4 promoted the expression of osteoprotegerin depending on the time of exposure. This effect may play an important role in the regulation of the energy metabolism in the whole body.

Topics: Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cell Survival; Energy Metabolism; Gene Expression Regulation; Humans; Inflammation; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Interleukin-4; Lipids; Obesity; Osteoblasts; Osteoprotegerin; Phosphorylation

Topics: Animals; Blood Glucose; Chondroitin Sulfates; Diabetes Complications; Diabetes Mellitus, Experimental; Female; Gene Expression Regulation; Inflammation; Osteoporosis; Osteoprotegerin; Oxidative Stress; RANK Ligand; Rats; Rats, Sprague-Dawley

To investigate the relationship between osteocalcin and osteoprotegerin as bone markers and inflammatory biomarkers such as adiponectin, leptin, tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) in children with nonalcoholic fatty liver disease (NAFLD).. This study included 40 obese children with NAFLD as the patient group and 40 healthy obese children of matched age, sex and BMI as the control group. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting blood glucose, fasting insulin, Homeostatic model assessment method of insulin resistance (HOMA-IR), lipid profile, osteocalcin, osteoprotegerin, adiponectin, leptin, TNF-α, and IL-6 were measured in all participants.. Children with NAFLD had a significant decrease in osteocalcin, osteoprotegerin and adiponectin level with a significant increase in TNF-α and IL-6 levels. We also found a significant positive correlation between osteocalcin level and adiponectin levels but a significant negative correlation of osteocalcin with each of leptin and TNF-α. However, there was a significant negative correlation between osteoprotegerin levels and both TNF-α and IL-6 levels. Moreover, adiponectin and TNF-α were significant predictors for osteocalcin, and IL-6 was a significant predictor for osteoprotegerin.. Adiponectin, leptin, TNF-α, and IL-6 have potential association with the changes of osteocalcin and osteoprotegerin levels in children with NAFLD.

Topics: Adipokines; Adiponectin; Alanine Transaminase; Aspartate Aminotransferases; Biomarkers; Blood Glucose; Body Mass Index; Case-Control Studies; Child; Cytokines; Humans; Inflammation; Insulin; Insulin Resistance; Interleukin-6; Male; Non-alcoholic Fatty Liver Disease; Obesity; Osteocalcin; Osteoprotegerin; Tumor Necrosis Factor-alpha

The major causes of failure after total knee arthroplasty (TKA) include prosthesis loosening and infection. This study aimed to investigate the role of carboxymethyl chitosan (CMC) in knee arthroplasty.. A total of 20 New Zealand white rabbits that were divided into two groups (10 in the control group and 10 in the chitosan group) were included in the study. They underwent TKA surgery, and all were implanted with titanium rod prostheses; the prosthesis in the chitosan group was coated with CMC. After 12 weeks, all rabbits were euthanized, and the following analyses of some specific surface membrane tissues around the prosthesis were performed: X-ray analysis; micro-computed tomography scan; haematoxylin and eosin, Van Gieson, and Von Kossa staining; reverse transcription polymerase chain reaction; and Western Blotting.. The result of CCK8 test showed CMC can promote cell proliferation and increase cell viability. Radiological result showed better amount of bone deposits and more bone formation in the chitosan group. HE staining result showed CMC reduces inflammation around the prosthesis. The VG and Von Kossa staining results showed CMC can promote bone deposition around prosthesis. And according to the results of PCR and WB, the OCN content was higher in the chitosan group, while the MMPs content was lower. The chitosan group has an increased OPG/RANKL ratio than the control group.. CMC can effectively inhibit the inflammatory response around the prosthesis and osteoclast activation and promote osteogenesis by interfering with the osteoprotegerin/receptor activator of nuclear factor kappa-Β ligand/receptor activator of nuclear factor kappa-Β signalling pathway.

Topics: Animals; Arthroplasty, Replacement, Knee; Chitosan; Inflammation; Osteogenesis; Osteoprotegerin; Rabbits; RANK Ligand; X-Ray Microtomography

Inflammation plays a major role in the development of metabolic syndrome (MetS) and its progression. Recent studies have shown that pentraxin-3 (PTX-3), osteoprogerin (OPG), and tumor necrosis factor-alpha (TNF-α) are key factors in MetS pathophysiology, but evidence for endorsing their clinical use is currently unclear and insufficient.. The study aimed to evaluate the association between the inflammatory biomarkers' levels and the severity of MetS.. The study was observational, transversal, prospective, cohort, and analytical type. We enrolled 80 patients (M:F = 1, mean age = 55 ± 10.77 years) who met MetS criteria. The study protocol included: medical history, physical examination, 6-min walk test distance (6MWTD), biochemical tests, electrocardiogram, echocardiography, and carotid ultrasonography. We also performed plasmatic measurement of PTX-3, OPG, and TNF-α, in addition to standard biochemical tests.. PTX-3 was correlated with the severity of MetS, with other inflammatory parameters and cardiovascular tests. CCA-IMT and 6MWTD are useful in differentiating between mild and severe MetS.

Topics: Biomarkers; Body Mass Index; C-Reactive Protein; Female; Humans; Inflammation; Male; Metabolic Syndrome; Middle Aged; Osteoprotegerin; Prospective Studies; Risk Assessment; Risk Factors; ROC Curve; Serum Amyloid P-Component; Tumor Necrosis Factor-alpha; Waist Circumference

Chronic pediatric inflammatory bowel disease (IBD) leads to lack of bone accrual, bone loss, and increased fractures. Presently there is no cure, and many IBD treatments incur negative side effects. We previously discovered treatment with exogenous irisin resolved inflammatory changes in the colon, gut lymphatics, and bone in a mild IBD rodent model. Here we assess irisin treatment in severe IBD induced via dextran sodium sulfate (DSS). Male Sprague Dawley rats (2-mo-old) were untreated (Con) or given 2% DSS in drinking water. In week two, half of each group (Con + Ir and DSS + Ir) received injections of recombinant irisin (i.p., 2x/wk). After 4 weeks, gut inflammation was associated with declines in bone mineral density and cancellous bone volume. Furthermore, elevated osteocyte TNF-α, interleukin-6, RANKL, OPG, and sclerostin corresponded with higher osteoclast surfaces and lower bone formation rate in DSS animals as well as lower ultimate load. While irisin treatment improved colon inflammation, there were no improvements in bone density or bone mechanical properties; however, irisin elevated bone formation rate, decreased osteoclast surfaces, and reduced osteocyte pro-inflammatory factors. These data highlight the negative impact of chronic gut inflammation on bone as well as the therapeutic potential of irisin as an anti-inflammatory treatment.

Topics: Animals; Biomechanical Phenomena; Body Weight; Bone and Bones; Bone Density; Bone Morphogenetic Proteins; Bone Resorption; Cancellous Bone; Colitis; Colon; Dextran Sulfate; Femur Neck; Fibronectins; Gastrointestinal Tract; Genetic Markers; Inflammation; Intestinal Mucosa; Lymphatic Vessels; Male; Osteocytes; Osteogenesis; Osteoprotegerin; RANK Ligand; Rats, Sprague-Dawley; Tibia; Tomography, X-Ray Computed; Tumor Necrosis Factor-alpha; Weight-Bearing

Chronic kidney disease (CKD) is an irreversible loss of kidney function, and it represents a major global public health burden due to both its prevalence and its continuously increasing incidence. Mineral bone disorders (MBDs) constitute a hallmark of CKD, and alongside cardiovascular complications, they underlie a poor prognosis for these patients. Thus, our study focused on novel CKD biomarker patterns and their impact on the clinical staging of the disease. As a first testing approach, the relative expression levels of 105 proteins were assessed by the Proteome Profiler Cytokine Array Kit for pooled CKD stage 2-4 serum samples to establish an overall view regarding the proteins involved in CKD pathogenesis. Among the molecules that displayed significant dysregulation in the CKD stages, we further explored the involvement of Dickkopf-related protein 1 (Dkk-1), a recognised inhibitor of the Wnt signalling pathway, and its crosstalk with 1,25OH

Topics: Aged; Algorithms; Biomarkers; Bone Density; Bone Diseases; Calcitriol; Cross-Sectional Studies; Female; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Interleukin-6; Male; Middle Aged; Osteocalcin; Osteopontin; Osteoprotegerin; Phenotype; Prognosis; Proteome; Renal Insufficiency, Chronic; Tumor Necrosis Factor-alpha; Wnt Signaling Pathway

Information about the tissue characteristics of abdominal aortic aneurysms (AAAs), some of which may be reflected in the serum, can help to elucidate AAA pathogenesis and identify new AAA biomarkers. This information would be beneficial not only for diagnostics and follow-up but also for potential therapeutic intervention. Therefore, the aim of our study was to compare the expression of structural proteins, immune factors (T and B lymphocytes, macrophages, neutrophils and pentraxin 3 (PTX3)), osteoprotegerin (OPG), microvessels and hypoxic cells in AAA and nonaneurysmal aortic walls. We examined specimens collected during surgery for AAA repair (n = 39) and from the abdominal aortas of kidney donors without AAA (n = 8). Using histochemical and immunohistochemical methods, we quantified the areas positive for smooth muscle actin, desmin, elastin, collagen, OPG, CD3, CD20, MAC387, myeloperoxidase, PTX3, and hypoxia-inducible factor 1-alpha and the density of CD31-positive microvessels. AAA samples contained significantly less actin, desmin, elastin and OPG, more collagen, macrophages, neutrophils, T lymphocytes, B lymphocytes, hypoxic cells and PTX3, and a greater density of vasa vasorum (VV) than those in non-AAA samples. Hypoxia positively correlated with actin and negatively correlated with collagen. Microvascular density was related to inflammatory cell infiltrates, hypoxia, PTX3 expression and AAA diameter. The lower OPG expression in AAAs supports the notion of its protective role in AAA remodeling. AAA contained altered amounts of structural proteins, implying reduced vascular elasticity. PTX3 was upregulated in AAA and colocalized with inflammatory infiltrates. This evidence supports further evaluation of PTX3 as a candidate marker of AAA. The presence of aortic hypoxia, despite hypervascularization, suggests that hypoxia-induced neoangiogenesis may play a role in AAA pathogenesis. VV angiogenesis of the AAA wall increases its vulnerability.

Topics: Adult; Aged; Aortic Aneurysm, Abdominal; Biomarkers; C-Reactive Protein; Case-Control Studies; Comorbidity; Female; Humans; Hypoxia; Immunohistochemistry; Inflammation; Male; Middle Aged; Neovascularization, Pathologic; Osteoprotegerin; Serum Amyloid P-Component

Delayed bone healing, especially in long bones poses one of the biggest problems in orthopeadic and reconstructive surgery and causes tremendous costs every year. There is a need for exploring the causes in order to find an adequate therapy. Earlier investigations of human scaphoid non-union revealed an elevated osteoclast activity, accompanied by upregulated levels of TGF-beta and RANKL. Interestingly, scaphoid non-union seemed to be well vascularized.. In the current study, we used a murine femur-defect model to study atrophic non unions over a time-course of 10 weeks. Different time points were chosen, to gather insights into the dynamic processes of non-union establishment.. Histological analyses as well as western blots and qRT-PCR indicated enhanced osteoclast activity throughout the observation period, paralleled by elevated levels of TGF-beta, TNF-alpha, MMP9, MMP13 and RANKL, especially during the early phases of non-union establishment. Interestingly, elevated levels of these mediators decreased markedly over a period of 10 weeks, as inflammatory reaction during non-union establishment seemed to wear out. To our surprise, osteoblastogenesis seemed to be unaffected during early stages of non-union establishment.. Taken together, we gained first insights into the establishment process of atrophic non unions, in which inflammatory processes accompanied by highly elevated osteoclast activity seem to play a leading role.

Topics: Animals; Atrophy; Cell Proliferation; Cytokines; Disease Models, Animal; Female; Fractures, Ununited; Inflammation; Inflammation Mediators; Male; Mice, Inbred C57BL; Osteoblasts; Osteoclasts; Osteoprotegerin; RANK Ligand

A clinically meaningful impairment of bone mass secondary to malabsorption is frequent in untreated celiac disease. In adult patients, a rigorous gluten-free diet (GFD) significantly improves, but does not always normalize, bone mineral density (BMD). The reason for this marginal response is unclear. Accordingly, we evaluated the role of both local and systemic factors for bone loss in celiac patients on long-term GFD.. In a prospective cohort, 22 patients with low lumbar and/or femoral BMD and 22 with normal BMD underwent bone and mineral metabolism evaluation: we tested calcium, phosphate, parathyroid hormone, and vitamin D; telopeptide of type I collagen, a bone resorption index; propeptide of type I procollagen, a bone neoformation index; receptor antagonist of NF-kB ligand, an osteoclast-stimulating factor; osteoprotegerin (OPG), a decoy receptor for RANKL. Sunlight exposure and physical exercise were measured.. Patients with bone loss showed prevalently osteopenia, severe osteoporosis was rare. In comparison with normal BMD patients, they showed higher serum OPG, telopeptide, and lower serum propeptide, suggesting an increased bone turnover. Lumbar T-score was negatively correlated with OPG, telopeptide and RANKL and positively with propeptide. Propeptide was negatively correlated with OPG and telopeptide. OPG was positively correlated with telopeptide.. The persistent activation of inflammation should be considered the main pathophysiological mechanism for bone defect in celiac disease patients with bone loss on long-term GFD. High levels of OPG, an attempt at protective mechanism, and low levels of propeptide of type I procollagen, reflecting an insufficient matrix production, characterize this subgroup of patients.

Topics: Adult; Bone Density; Bone Diseases, Metabolic; Celiac Disease; Cohort Studies; Diet, Gluten-Free; Female; Humans; Inflammation; Osteoporosis; Osteoprotegerin; Peptide Fragments; Procollagen; Prospective Studies

Although the relationship between positive and negative symptoms of psychosis and dyslipidemia has been thoroughly investigated in recent studies, the potential link between depression and lipid status is still under-investigated. We here examined the association between lipid levels and depressive symptomatology in patients with psychotic disorders, in addition to their possible inflammatory associations. Participants (n = 652) with the following distribution: schizophrenia, schizophreniform and schizoaffective disorder (schizophrenia group, n = 344); bipolar I, II, NOS, and psychosis NOS (non-schizophrenia group, n = 308) were recruited consecutively from the Norwegian Thematically Organized Psychosis (TOP) Study. Clinical data were obtained by Positive and Negative Syndrome Scale (PANSS), and Calgary Depression Scale for Schizophrenia (CDSS). Blood samples were analyzed for total cholesterol (TC), low-density lipoprotein (LDL), triglyceride (TG), C-reactive protein (CRP), soluble tumor necrosis factor receptor 1(sTNF-R1), osteoprotegerin (OPG), and interleukin 1 receptor antagonist (IL-1Ra). After adjusting for age, gender, BMI, smoking, and dyslipidemia-inducing antipsychotics, TC and LDL scores showed significant associations with depression [β = 0.13, p = 0.007; β = 0.14, p = 0.007], and with two inflammatory markers: CRP [β = 0.14, p = 0.007; β = 0.16, p = 0.007] and OPG [β = 0.14, p = 0.007; β = 0.11, p = 0.007]. Total model variance was 17% for both analyses [F(12, 433) = 8.42, p < 0.001; F(12, 433) = 8.64, p < 0.001]. Current findings highlight a potential independent role of depression and inflammatory markers, CRP and OPG in specific, in the pathophysiology of dyslipidemia in psychotic disorders.

Topics: Adult; C-Reactive Protein; Cholesterol, LDL; Comorbidity; Depression; Dyslipidemias; Female; Humans; Inflammation; Interleukin 1 Receptor Antagonist Protein; Male; Norway; Osteoprotegerin; Psychotic Disorders; Receptors, Tumor Necrosis Factor, Type I; Schizophrenia; Triglycerides; Young Adult

Metformin, an anti-hyperglycemic agent used for type 2 diabetes, has recently been found to have more effects apart from glucose regulation. We found that, in ultra-high-molecular-weight polyethylene particle-induced osteolysis mouse models, metformin had bone protect property and reduced the negative regulator of bone formation sclerostin (SOST) and Dickkopf-related protein 1 (DKK1), and increased osteoprotegerin (OPG) secretion and the ratio of OPG/Receptor Activator for Nuclear Factor-κB Ligand (RANKL). In vitro, we established a 3D co-culture system in which metformin affects osteoblasts and osteoclasts through mature osteocytes secretion. Metformin (50 μM) significantly decreased SOST and DKK1 mRNA expression, stimulating alkaline phosphatase activity and proliferation of osteoblast, and increased OPG secretion and the ratio of OPG/RANKL, inhibiting osteoclastogenesis. Moreover, the effect on OPG was reversed by adenosine 5'-monophosphate-activated protein kinase inhibitor, Compound C. Our finding suggests that metformin induces differentiation and mineralization of osteoblasts, while inhibits osteoclastogenesis via mature osteocytes secretion. Therefore, the drug might be beneficial for not only diabetes but also in other bone disorders by acting on mature osteocytes.

Topics: Adaptor Proteins, Signal Transducing; Adenylate Kinase; Animals; Bone and Bones; Cell Differentiation; Cell Proliferation; Cells, Cultured; Coculture Techniques; Disease Models, Animal; Glycoproteins; Inflammation; Intercellular Signaling Peptides and Proteins; Male; Metformin; Mice, Inbred C57BL; Models, Biological; Organ Size; Osteocytes; Osteogenesis; Osteolysis; Osteoprotegerin; Phosphorylation; Polyethylenes; Protective Agents; RANK Ligand; Skull

Inflammatory mediator prostaglandin E

Topics: Animals; Bone Resorption; Cell Differentiation; Cell Line; Coculture Techniques; Dinoprostone; Inflammation; Interleukin-6; Leukocytes, Mononuclear; Lipopolysaccharides; Mice; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; Periodontal Ligament; Prostaglandin-E Synthases; RANK Ligand; RAW 264.7 Cells; Tartrate-Resistant Acid Phosphatase; Thiazoles

Topics: Aorta, Thoracic; Calcinosis; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Hematinics; Humans; Inflammation; Nutritional Physiological Phenomena; Osteoprotegerin; Prognosis; Renal Dialysis; Risk Factors

Inflammatory bone markers may play a role in the antidepressant actions of (R)-ketamine in susceptible mice after chronic social defeat stress (CSDS). In this study, we compared the effects of (R)-ketamine and its final metabolite (2R,6R)-hydroxynorketamine (HNK) in depression-like phenotypes, inflammatory bone markers and bone mineral density (BMD) in CSDS susceptible mice. We measured plasma levels of inflammatory bone markers, which included osteoprotegerin (OPG), receptor activator of nuclear factor κB ligand (RANKL), and osteopontin after behavioral tests. (R)-ketamine, but not (2R,6R)-HNK, elicited rapid and sustained antidepressant effects in CSDS susceptible mice. Furthermore, (R)-ketamine, but not (2R,6R)-HNK, significantly improved the increased plasma levels of RANKL and decreased OPG/RANKL ratio in CSDS susceptible mice. Moreover, (R)-ketamine, but not (2R,6R)-HNK, significantly attenuated the decreased BMD in CSDS susceptible mice. These findings demonstrate that (R)-ketamine may have beneficial effects in depression-like phenotype and abnormalities in bone functions of CSDS susceptible mice. It is, therefore, likely that (R)-ketamine would be a potential therapeutic drug for abnormalities in bone metabolism in depressed patients.

Topics: Animals; Antidepressive Agents; Biomarkers; Bone Density; Depression; Depressive Disorder; Disease Models, Animal; Inflammation; Ketamine; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Osteopontin; Osteoprotegerin; RANK Ligand; Stress, Psychological

Hepatic osteodystrophy is multifactorial in its pathogenesis. Numerous studies have shown that impairments of the hepatic growth hormone/insulin-like growth factor-1 axis (GH/IGF-1) are common in patients with non-alcoholic fatty liver disease, chronic viral hepatitis, liver cirrhosis, and chronic cholestatic liver disease. Moreover, these conditions are also associated with low bone mineral density (BMD) and greater fracture risk, particularly in cortical bone sites. Hence, we addressed whether disruptions in the GH/IGF-1 axis were causally related to the low bone mass in states of chronic liver disease using a mouse model of liver-specific GH-receptor (GHR) gene deletion (Li-GHRKO). These mice exhibit chronic hepatic steatosis, local inflammation, and reduced BMD. We then employed a crossing strategy to restore liver production of IGF-1 via hepatic IGF-1 transgene (HIT). The resultant Li-GHRKO-HIT mouse model allowed us to dissect the roles of liver-derived IGF-1 in the pathogenesis of osteodystrophy during liver disease. We found that hepatic IGF-1 restored cortical bone acquisition, microarchitecture, and mechanical properties during growth in Li-GHRKO-HIT mice, which was maintained during aging. However, trabecular bone volume was not restored in the Li-GHRKO-HIT mice. We found increased bone resorption indices in vivo as well as increased basal reactive oxygen species and increased mitochondrial stress in osteoblast cultures from Li-GHRKO and the Li-GHRKO-HIT compared with control mice. Changes in systemic markers such as inflammatory cytokines, osteoprotegerin, osteopontin, parathyroid hormone, osteocalcin, or carboxy-terminal collagen cross-links could not fully account for the diminished trabecular bone in the Li-GHRKO-HIT mice. Thus, the reduced serum IGF-1 associated with hepatic osteodystrophy is a main determinant of low cortical but not trabecular bone mass. © 2017 American Society for Bone and Mineral Research.

Topics: Animals; Biomechanical Phenomena; Bone Density; Bone Diseases, Metabolic; Cancellous Bone; Chronic Disease; Cortical Bone; Cytokines; Fatty Liver; Inflammation; Inflammation Mediators; Insulin-Like Growth Factor I; Liver; Mice, Inbred C57BL; Mice, Transgenic; Organ Size; Organ Specificity; Osteoblasts; Osteopontin; Osteoprotegerin; Receptors, Somatotropin; Transgenes; X-Ray Microtomography

Orthosiphon stamineus (OS) or Misai Kucing (Java tea) is a popular herbal supplement from Southeast Asia for various metabolic, age-related diseases. This study investigated the potential use of OS leaf extracts to ameliorate osteoporosis in ovariectomized rats.. Fifty-six female Sprague-Dawley rats were randomly allocated into eight groups (n = 7): SHAM (healthy sham control); OVX (ovarietomized) nontreated rats (negative control); OVX + Remifemin (100 mg/kg body weight), and 2% green tea extract (positive controls); OVX + OS 50% ethanolic and aqueous extracts, both at either 150 or 300 mg/kg. After 16 weeks, the rats' bones and blood were evaluated for osteoporosis indicators (protein and mRNA expressions), micro-computed tomography for bone histomorphometry, and three-point bending test for tibia mechanical strength.. The extracts dose-dependently and significantly (P < 0.05) improved bone strength and flexibility, bone mineral density, bone formation protein markers (P1NP), and bone histomorphometry. All extracts reduced the inflammation biomarker (interleukin-6). The extracts up-regulated osteoblastogenesis (bone morphogenetic protein-2) and collagen-1 synthesis (collagen type 1 alpha-1) mRNA expressions, and down-regulated bone resorption (TNFSF11 and nuclear factor-kappa B) mRNA expressions. Both the water and 50% ethanolic extract were effective. The effective dose is equivalent to 25 to 50 mg/kg extract for humans.. The extract showed bone-protective and antiosteoporotic effects (improving bone strength, flexibility, bone density, and bone morphometry) by reducing inflammation and the bone resorption biomarkers, while enhancing bone formation biomarkers and collagen synthesis.

Topics: Animals; Bone and Bones; Bone Density; Bone Morphogenetic Protein 2; Bone Resorption; Collagen Type I; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Gene Expression; Humans; Inflammation; Interleukin-6; NF-kappa B; Orthosiphon; Osteoporosis, Postmenopausal; Osteoprotegerin; Ovariectomy; Peptide Fragments; Plant Extracts; Plant Leaves; Pliability; Procollagen; Random Allocation; RANK Ligand; Rats; Rats, Sprague-Dawley; Teas, Herbal; X-Ray Microtomography

Although it has been well established that osteogenic differentiation of bone mesenchymal stem cells (bMSCs) as well as osteoclastic differentiation of macrophages can be manipulated by the nanostructure of biomaterial surfaces, the interactions among the effects of the surface on immune cells and bMSCs remained unknown. Therefore, in this study, the osteogenic behaviors and secretion of osteoclastogenesis-related cytokines of human bMSCs on TiO

Topics: Bone and Bones; Cell Adhesion; Cell Movement; Cell Proliferation; Cells, Cultured; Culture Media, Conditioned; Cytokines; Gene Expression Regulation; Humans; Implants, Experimental; Inflammation; Macrophage Colony-Stimulating Factor; Macrophages; Mesenchymal Stem Cells; Monocytes; Nanostructures; Osseointegration; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Solubility; Surface Properties; Titanium

Periodontitis, an infective disease caused by oral pathogens and the intrinsic aging process, results in the destruction of periodontal tissues and the loss of alveolar bone. This study investigated whether

Topics: Alveolar Bone Loss; Animals; Cathepsin K; Collagen Type I; Collagen Type I, alpha 1 Chain; Gingiva; Inflammation; Interleukin-1beta; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 8; Models, Animal; NF-kappa B; Osteoporosis; Osteoprotegerin; Periodontal Diseases; Periodontitis; Plant Extracts; Proto-Oncogene Proteins c-fos; RANK Ligand; Rats; Rats, Inbred F344; RNA, Messenger; Tartrate-Resistant Acid Phosphatase; Transcription Factors; X-Ray Microtomography; Zingiberaceae

we aimed to study systemic sclerosis patients in order to assess osteoprotegerin/Receptor activator of nuclear factor-kB ligand (OPG/RANKL) system and find the relation of these biomarkers with the clinical features of the disease, the carotid intima thickness, markers of inflammation, lipid profile, and other laboratory characteristics.. both the level of (RANKL), (OPG) in sera of participants, in 30 (SSc) patients and the atherosclerotic changes affecting the common carotid artery were measured and, were compared to 30 healthy controls matched for age and sex. All participants were assessed clinically and subjected to the Revised Medsger SSc severity scale and underwent carotid Doppler ultrasound examination.. OPG, RANKL, and RANKL/OPG were 1.9 ± 0.4 ng/ml, 24.3 ± 17.25 ng/ml, and 13.5 ±9.8 versus 0.77 ± 0.25 ng/ml, 7.13 ± 3.02 ng/ml, and 9.6 ± 3.1 in the SSc patients and the controls with significance (P = 0.001, P = 0.001, P = 0.045) respectively. The OPG- RANKL axis in the SSc patients correlated significantly with carotid intima thickness, arthritis, arthralgia, inflammatory markers, Medsger joint, Medsger vascular, Medsger skin, and dyslipidemia.. In cardiovascular risks, OPG serum level might increase as a preventive compensatory mechanism to neutralize the RANKL level increment. The determination of the OPG-RANKL system is a diagnostic indicator for the intensity of vascular calcification and atherosclerosis in SSc patients.

Topics: Adult; Atherosclerosis; Biomarkers; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; Phenotype; RANK Ligand; Risk Factors; Scleroderma, Systemic

Accumulating evidence indicates that the immune and skeletal systems interact with each other through various regulators during the osteoclastogenic process. Among these regulators, the bioactive lipid sphingosine-1-phosphate (S1P), which is synthesized by sphingosine kinase 1/2 (SPHK1/2), has recently been recognized to play a role in immunity and bone remodeling through its receptor sphingosine-1-phosphate receptor 1 (S1PR1). However, little is known regarding the potential role of S1PR1 signaling in inflammatory bone loss. We observed that SPHK1 and S1PR1 were upregulated in human apical periodontitis, accompanied by macrophage infiltration and enhanced expression of receptor activator of NF-κB ligand (RANKL, an indispensable factor in osteoclastogenesis and bone resorption) and increased numbers of S1PR1-RANKL double-positive cells in lesion tissues. Using an in vitro co-culture model of macrophages and bone marrow stromal cells (BMSCs), it was revealed that in the presence of lipopolysaccharide (LPS) stimulation, macrophages could significantly induce SPHK1 activity, which resulted in activated S1PR1 in BMSCs. The activated S1P-S1PR1 signaling was responsible for the increased RANKL production in BMSCs, as S1PR1-blockage abolished this effect. Applying a potent S1P-S1PR1 signaling modulator, Fingolimod (FTY720), in a Wistar rat apical periodontitis model effectively prevented bone lesions in vivo via downregulation of RANKL production, osteoclastogenesis, and bone resorption. Our data unveiled the regulatory role of SPHK1-S1PR1-RANKL axis in inflammatory bone lesions and proposed a potential therapeutic intervention by targeting this cell-signaling pathway to prevent bone loss. © 2018 American Society for Bone and Mineral Research.

Topics: Adult; Aged; Animals; Autophagy; Biomarkers; Bone Resorption; Cell Communication; Down-Regulation; Female; Humans; Inflammation; Macrophages; Male; Mesenchymal Stem Cells; Mice; Middle Aged; Models, Biological; Osteogenesis; Osteoprotegerin; Periapical Diseases; Phosphotransferases (Alcohol Group Acceptor); RANK Ligand; Rats, Wistar; RAW 264.7 Cells; Receptors, Lysosphingolipid; Signal Transduction; Up-Regulation; Young Adult

The aim of the study was to investigate the effects of colchicine on cytokine production, apoptosis, alveolar bone loss, and oxidative stress in an experimental model of periodontitis in rats.. Forty-eight rats were divided equally into four groups: healthy (H); periodontitis (P); periodontitis+colchicine low dose (CL, 30 μg/kg/day), and periodontitis+colchicine high dose (CH, 100 μg/kg/day). After 11 days, interleukin (IL) -1β, IL-8, and IL-10 were analyzed in gingival samples using Enzyme-Linked ImmunoSorbent Assay. Receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), total oxidative stress (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) were measured in gingiva and serum. Alveolar bone volume was evaluated via micro-CT. Apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay in histological sections.. Colchicine treatment significantly reduced IL-1β, IL-8, RANKL, RANKL/OPG, TOS, OSI, and bone volume ratio levels, and increased TAS levels compared to group P (p < 0.05). High dose colchicine treatment (CH) significantly decreased TUNEL+ cell counts compared to group P (p < 0.05).. These finding suggest that colchicine has a prophylactic potential for the prevention of periodontal tissue destruction through anti-inflammatory, anti-oxidative, anti-apoptotic, and bone-protective effects.

Topics: Alveolar Bone Loss; Animals; Apoptosis; Colchicine; Inflammation; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar

To examine whether fluctuations in training load during an Olympic year lead to changes in bone mineral densities and factors that regulate bone (sclerostin, osteoprotegerin and receptor activator of nuclear factor kappa-B ligand), energy metabolism (insulin-like growth factor-1 and leptin), and inflammation (tumor necrosis factor-α and interleukin 6) in elite heavyweight female rowers.. Blood samples were drawn from 15 female heavyweight rowers (27.0 ± 0.8 yr, 80.9 ± 1.3 kg, 179.4 ± 1.4 cm) at baseline (T1-45 wk before Olympic Games) and after 7, 9, 20, 25, and 42 wk (T1-6, respectively). Ongoing nutritional counseling was provided. Total weekly training load was recorded over the week before each time point. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry at T1 and T6.. Total BMD increased significantly before to after training (+0.02 g·cm), but was below the least significant change (±0.04 g·cm). Osteoprotegerin, insulin-like growth factor-1, and leptin remained stable across all time points. Fluctuations in training load (high vs low) were accompanied by parallel changes in tumor necrosis factor-α (2.1 ± 0.2 vs 1.5 ± 0.2 pg·mL), interleukin 6 (1.2 ± 0.08 vs 0.8 ± 0.09 pg·mL), and sclerostin (high: 993 ± 109 vs low: 741 ± 104 pg·mL).. In this population of young female athletes with suitable energy availability, sclerostin and inflammation markers responded to fluctuations in training load, whereas BMD and bone mineral content were stable during the season, suggesting that training load periodization is not harmful for the bone health in athletes.

Topics: Adaptor Proteins, Signal Transducing; Adult; Biomarkers; Bone and Bones; Bone Density; Bone Morphogenetic Proteins; Energy Metabolism; Female; Genetic Markers; Humans; Inflammation; Insulin-Like Growth Factor I; Interleukin-6; Leptin; Osteoprotegerin; Physical Conditioning, Human; Tumor Necrosis Factor-alpha; Water Sports

To evaluate the expression of TNF-α, IL-6, IFN-γ, TGF-β, IL-4, IL-10, RANKL, RANK and OPG on mouse calvarial bone treated with MTA, Geristore. Bone wounds were made on the heads of C57BL/6 mice, breaking the periosteum and the cortical surface of the calvaria. Each repair agent was inserted into sectioned Eppendorf microtubes and placed on the bone wound, and soft tissues were sutured. At 14 and 21 days, animals were sacrificed and the treated region was dissected. The calvaria bone was removed, and RNA was extracted. mRNA expression of the aforementioned cytokines was assessed using real-time PCR. Data were analysed by nonparametric methods, including the Mann-Whitney and Kruskal-Wallis tests (P < 0.05).. Following treatment with Emdogain. The clinical indication of these repair agents depends on the root resorption diagnosis. Whilst MTA and Emdogain

Topics: Aluminum Compounds; Animals; Calcium Compounds; Cytokines; Dental Enamel Proteins; Drug Combinations; Gene Expression Regulation; Glass Ionomer Cements; Inflammation; Interferon-gamma; Interleukin-10; Interleukin-4; Interleukin-6; Mice; Mice, Inbred C57BL; Osteoprotegerin; Oxides; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Resins, Synthetic; RNA, Messenger; Root Resorption; Silicates; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Topics: Animals; Bone and Bones; Bone Regeneration; Cell Differentiation; Disease Models, Animal; Eicosapentaenoic Acid; Gene Expression Profiling; Gene Expression Regulation; Inflammation; Mice; Osteoblasts; Osteoclasts; Osteogenesis; Osteolysis; Osteoprotegerin; RANK Ligand; Signal Transduction; Tumor Necrosis Factor-alpha

Tissue cross-talk is emerging as a determinant way to coordinate the different organs implicated in glucose homeostasis. Among the inter-organ communication factors, muscle-secreted myokines can modulate the function and survival of pancreatic beta-cells. Using primary human myotubes from soleus, vastus lateralis and triceps brachii muscles, we report here that the impact of myokines on beta-cells depends on fiber types and their metabolic status. We show that Type I and type II primary myotubes present specific mRNA and myokine signatures as well as a different sensitivity to TNF-alpha induced insulin resistance. Finally, we show that angiogenin and osteoprotegerin are triceps specific myokines with beta-cell protective actions against proinflammatory cytokines. These results suggest that type I and type II muscles could impact insulin secretion and beta-cell mass differentially in type 2 diabetes through specific myokines secretion.

Topics: Cytokines; Diabetes Mellitus, Type 2; Homeostasis; Humans; Inflammation; Insulin Resistance; Insulin-Secreting Cells; Muscle Cells; Muscle Fibers, Skeletal; Muscle, Skeletal; Osteoprotegerin; Primary Cell Culture; Ribonuclease, Pancreatic; Tumor Necrosis Factor-alpha

Strontium (Sr) has shown effectiveness for stimulating bone remodeling. Nevertheless, the exact therapeutic values are not established yet. Authors hypothesized that local application of Sr-enriched ceramics would enhance bone remodeling in constant osteoporosis of rabbits' femoral neck bone. Seven different bone conditions were analyzed: ten healthy rabbits composed a control group, while other twenty underwent ovariectomy and were divided into three groups. Bone defect was filled with hydroxyapatite 30% (HAP) and tricalcium phosphate 70% (TCP) granules in 7 rabbits, 5% of Sr-enriched HAP/TCP granules in 7, but sham defect was left unfilled in 6 rabbits. Bone samples were obtained from operated and non-operated legs 12 weeks after surgery and analyzed by histomorphometry and immunohistochemistry (IMH). Mean trabecular bone area in control group was 0.393 mm2, in HAP/TCP - 0.226 mm2, in HAP/TCP/Sr - 0.234 mm2 and after sham surgery - 0.242 mm2. IMH revealed that HAP/TCP/Sr induced most noticeable increase of nuclear factor kappa beta 105 (NFkB 105), osteoprotegerin (OPG), osteocalcin (OC), bone morphogenetic protein 2/4 (BMP 2/4), collagen type 1α (COL-1α), interleukin 1 (IL-1) with comparison to intact leg; NFkB 105 and OPG rather than pure HAP/TCP or sham bone. We concluded that Sr-enriched biomaterials induce higher potential to improve bone regeneration than pure bioceramics in constant osteoporosis of femoral neck bone. Further studies on bigger osteoporotic animals using Sr-substituted orthopedic implants for femoral neck fixation should be performed to confirm valuable role in local treatment of osteoporotic femoral neck fractures in humans.

Topics: Animals; Biocompatible Materials; Bone Regeneration; Bone Remodeling; Bone Substitutes; Calcium Phosphates; Ceramics; Durapatite; Female; Femur; Femur Head; Immunohistochemistry; Inflammation; Osteoporosis; Osteoprotegerin; Rabbits; Strontium

Low-dose radiotherapy (LD-RT) for benign inflammatory and/or bone destructive diseases has been used long. Therefore, mechanistic investigations on cells being present in joints are mostly made in an inflammatory setting. This raises the question whether similar effects of LD-RT are also seen in healthy tissue and thus might cause possible harmful effects. We performed examinations on the functionality and phenotype of key cells within the joint, namely on fibroblast-like synoviocytes (FLS), osteoclasts and osteoblasts, as well as on immune cells. Low doses of ionizing radiation showed only a minor impact on cytokine release by healthy FLS as well as on molecules involved in cartilage and bone destruction and had no significant impact on cell death and migration properties. The bone resorbing abilities of healthy osteoclasts was slightly reduced following LD-RT and a positive impact on bone formation of healthy osteoblasts was observed after in particular exposure to 0.5 Gray (Gy). Cell death rates of bone-marrow cells were only marginally increased and immune cell composition of the bone marrow showed a slight shift from CD8⁺ to CD4⁺ T cell subsets. Taken together, our results indicate that LD-RT with particularly a single dose of 0.5 Gy has no harmful effects on cells of healthy joints.

Topics: Animals; Apoptosis; Bone Marrow Cells; Cartilage, Articular; Cell Movement; Cell Proliferation; Dose-Response Relationship, Drug; Fibroblasts; Inflammation; Joints; Mice, Inbred C57BL; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; Radiation, Ionizing; Synoviocytes; Transforming Growth Factor beta; Up-Regulation

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy that can be associated with focal bone erosions. Psoriasis usually precedes the psoriatic arthritis onset by an average of 10 years, but this relation is not yet fully elucidated. Pro-inflammatory cytokines, such as IL-33, OPN, IL-17, and TNF-α are involved in both psoriasis and PsA pathogenesis as well as in bone homeostasis. In this study, we have demonstrated that IL-33, OPN, IL-17, and TNF-α induced the release of a wide range of pro-osteoclastogenic factors from the skin, such as RANKL, that promote monocyte differentiation in osteoclasts. The addition of osteoprotegerin, a RANKL inhibitor, to monocyte cultures treated with supernatant from stimulated skin did not completely deplete osteoclast formation, suggesting that skin produced several additional pro-osteoclastogenic mediators, which could act in a RANKL-independent manner. Moreover, we have found that RANKL serum levels as well as osteoclast number and activity in psoriatic patients with and without arthritis, was influenced by severity of cutaneous disease. Our data demonstrate that psoriatic cutaneous inflammation contributes to bone damage.

Topics: Adult; Arthritis, Psoriatic; Bone and Bones; Bone Resorption; Cytokines; Female; Humans; Inflammation; Interleukin-17; Interleukin-33; Male; Monocytes; Osteoclasts; Osteogenesis; Osteopontin; Osteoprotegerin; Psoriasis; RANK Ligand; Tumor Necrosis Factor-alpha; Young Adult

Osteoprotegerin (OPG) is a novel regulator of endothelial cell function, angiogenesis, and vasculogenesis. We correlated expression levels of OPG with those of the angiogenic and inflammatory factors vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2) in proliferative diabetic retinopathy (PDR). We also examined expression of OPG in retinas from diabetic rats and diabetic patients and measured production of OPG by human retinal microvascular endothelial cells (HRMEC) and investigated its angiogenic activity.. Vitreous samples from 47 PDR and 28 nondiabetic patients, epiretinal membranes from 14 patients with PDR, human retinas (10 from diabetic patients and 10 from nondiabetic subjects), and rat retinas and HRMEC were studied by using enzyme-linked immunosorbent assay, immunohistochemistry, immunofluorescence, Western blot analysis, and RT-PCR. In vitro and in vivo angiogenesis assays were performed.. We showed a significant increase in the expression of OPG, VEGF, and MCP-1/CCL2 in a comparison between vitreous samples from PDR patients and those from nondiabetic controls. Significant positive correlations were found between levels of OPG and levels of VEGF and MCP-1/CCL2. In epiretinal membranes, OPG was expressed in vascular endothelial cells and stromal cells. Significant increases of OPG mRNA and protein were detected in the retinas from diabetic patients. The proinflammatory cytokines TNF-α and IL-1β, but not VEGF, MCP-1/CCL2 or thrombin, induced upregulation of OPG in HRMEC. Osteoprotegerin induced ERK1/2 and Akt phosphorylation in HRMEC and stimulated their migration. Osteoprotegerin potentiated the angiogenic effect of VEGF in the in vivo protein gelatin plug assay.. These results suggest that OPG is involved in PDR angiogenesis.

Topics: Animals; Blotting, Western; Chemokine CCL2; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Endothelial Cells; Epiretinal Membrane; Humans; Immunohistochemistry; Inflammation; Osteoprotegerin; Rats; Rats, Sprague-Dawley; Retina; Retinal Neovascularization; Retinal Vessels; Vascular Endothelial Growth Factor A; Vitreous Body

This study assessed the effect of curcumin as a photosensitizer in antimicrobial photodynamic therapy (aPDT) for the treatment of induced periodontitis in rats. Periodontitis was induced via a ligature around the mandibular first molar on the left side of 96 rats. The ligature was removed 7 days later, and the animals were randomized into four groups: NT, no local treatment; CUR, irrigation with curcumin solution (40 μM); LED, irradiation with a light-emitting diode (LED, InGaN, 465-485 nm, 200 mW/cm

Topics: Animals; Curcumin; Inflammation; Male; Mandible; Molar; Osteoprotegerin; Periodontitis; Photochemotherapy; Proliferating Cell Nuclear Antigen; RANK Ligand; Rats, Wistar; Tartrate-Resistant Acid Phosphatase

We evaluated if plasma levels of inflammatory markers are persistently altered in severe mental disorders with psychotic symptoms or associated with state characteristics in a longitudinal study.. Soluble tumor necrosis factor receptor 1 (sTNF-R1), interleukin-1 receptor antagonist (IL-1Ra), von Willebrand factor (VWF), and osteoprotegerin (OPG) were measured in schizophrenia (n = 69) and affective (n = 55) spectrum patients at baseline and at one-year follow-up, and compared to healthy controls (HC) (n = 92) with analysis of covariance. Association between change in symptoms and inflammatory markers was analyzed with mixed-effects models.. sTNF-R1 was higher in the schizophrenia (P < 0.0001) and affective disorders (P = 0.02) compared to HC, while IL-1Ra was higher in schizophrenia (P = 0.01) compared to HC at one year follow-up. There were no significant differences between schizophrenia and affective groups; however, levels in the affective group were in between schizophrenia and HC for sTNF-R1 and IL-1Ra. There were no significant associations between change in symptoms and inflammatory markers.. Persistently increased sTNF-R1 and IL-1Ra after one year in patients with severe mental disorders primarily reflecting data from the schizophrenia group may suggest that inflammation is a trait phenomenon, and not only the result of stress-related mechanisms associated with acute episodes.

Topics: Adolescent; Adult; Bipolar Disorder; Depressive Disorder, Major; Female; Follow-Up Studies; Humans; Inflammation; Interleukin 1 Receptor Antagonist Protein; Male; Middle Aged; Osteoprotegerin; Psychotic Disorders; Receptors, Tumor Necrosis Factor, Type I; Schizophrenia; von Willebrand Factor; Young Adult

Our recent work showed that daily injections of osteoprotegerin (OPG)-immunoglobulin fragment complex (OPG-Fc) completely restore the function of fast-twitch extensor digitorum longus muscles in dystrophic mdx mice, a murine model of Duchenne muscular dystrophy. However, despite marked improvements, OPG-Fc was not as effective in preventing the loss of function of slow-twitch soleus and diaphragm muscles. Because β

Topics: Adrenergic beta-2 Receptor Agonists; Animals; Formoterol Fumarate; Inflammation; Male; Mice, Inbred C57BL; Models, Biological; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch; Muscular Dystrophy, Animal; Osteoprotegerin; Receptors, Fc

Aseptic loosening secondary to periprosthetic inflammatory osteolysis results from the biological response to wear particles and is a leading cause of arthroplasty failure. The origin of this inflammatory response remains unclear. We aim to validate the definite link between endoplasmic reticulum (ER) stress and particle-induced inflammatory signaling pathways in periprosthetic osteolysis. We examine the histopathologic changes of osteolysis and the expression of specific biomarkers for ER-stress-mediated inflammatory signaling pathways (IRE1α, GRP78/Bip, c-Fos, NF-κB, ROS and Ca(2+)). Moreover, pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and osteoclastogenic molecules (VEGF, OPG, RANKL and M-CSF) were assessed in clinical interface membranes and murine periosteum tissues. We found wear particles to be capable of inducing ER stress in macrophages within clinical osteolytic interface membranes and murine osteolytic periosteum tissues and to be associated with the inflammatory response and osteoclastogenesis. Blocking ER stress with sodium 4-phenylbutyrate (4-PBA) results in a dramatic amelioration of particle-induced osteolysis and a significant reduction of ER-stress intensity. Simultaneously, this ER-stress blocker also lessens inflammatory cell infiltration, diminishes the capability of osteoclastogenesis and reduces the inflammatory response by lowering IRE1α, GRP78/Bip, c-Fos, NF-κB, ROS and Ca(2+) levels. Thus, ER stress plays an important role in particle-induced inflammatory osteolysis and osteoclastogenic reactions. The pharmacological targeting of ER-stress-mediated inflammatory signaling pathways might be an appealing approach for alleviating or preventing particle-induced osteolysis in at-risk patients.

Topics: Adolescent; Aged; Animals; Cytokines; Disease Models, Animal; Disease Progression; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Female; Humans; Inflammation; Inflammation Mediators; Male; Membranes; Mice; Middle Aged; Nanoparticles; NF-kappa B; Osteoclasts; Osteolysis; Osteoprotegerin; Periosteum; Prostheses and Implants; Prosthesis Failure; Radiography; RANK Ligand; Signal Transduction; Vascular Endothelial Growth Factor A

One of the most distinct features of middle ear cholesteatoma is bone destruction. Aetiology of cholesteatoma is thought to be multifactorial. Endotoxins produced by bacteria are thought to initiate the inflammation process in the middle ear leading to cholesteatoma. There are physiological differences in bone metabolism between men and women. The aim of our study was the immunohistochemical evaluation of the contents of two key components of the OPG/RANK/RANKL triad-RANKL and OPG in cholesteatoma, to analyse if there are any differences between the sexes and to evaluate the bacteria species isolated from cholesteatoma just before surgical treatment and to evaluate their plausible influence on the expression of OPG and RANKL in cholesteatoma. Twenty-one adult patients with acquired cholesteatoma who underwent surgery were analysed. There were no statistically significant differences in the expression of both regulators of osteoclastogenesis between the sexes. In 38.1 % patients cholesteatoma was not infected, whereas in 61.9 % patients various bacterial infections or mycosis were found. The most frequently isolated species was Pseudomonas aeruginosa (14.29 % infections) followed by Staphylococcus aureus (9.52 % infections). There were no statistically significant differences in expression of both OPG and RANKL between uninfected and infected cholesteatomas.

Topics: Adult; Bacterial Infections; Bone and Bones; Cholesteatoma; Female; Gene Expression Regulation, Bacterial; Humans; Immunohistochemistry; Inflammation; Male; Middle Aged; Osteoclasts; Osteogenesis; Osteoprotegerin; Pilot Projects; Pseudomonas aeruginosa; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Staphylococcus aureus

Macrophages and osteoclasts release proinflammatory factors and promote osteoclastogenesis following the phagocytosis of wear particles. During this pathological process, receptor of nuclear factor κB ligand (RANKL) and tumor necrosis factor (TNF)-α are critical factors contributing to resorption and the inflammatory response. The present study aimed to construct recombination lentivirus vectors carrying TNF-α small interfering (si)RNA and osteoprotegerin (OPG) cDNA, and to examine the effects of Lenti‑siTNFα‑OPG on the wear particle‑induced inflammatory response and osteoclastogenesis in a titanium (Ti) particle‑induced‑inflammatory response cell model. Lenti‑siTNFα‑OPG vectors were constructed and transnfected into RAW264.7 and MC3T3‑E1 cells, respectively, prior to particle stimulation. The protein levels of TNF‑α, OPG and RANKL were evaluated using western blot analysis and enzyme‑linked immunosorbent assays, and the mRNA expression levels of the inflammatory factors, TNF‑α, interleukin (IL)‑1β and IL‑6, as well as OPG and RANKL, were measured using reverse transcription‑quantitative polymerase chain reaction analysis. The activity of alkaline phosphatase (ALP) was examined using an ALP kit. In the presence of the Lenti‑siTNFα‑OPG vector, the mRNA expression levels of the inflammatory factors and RANKL were downregulated, as were the protein levels of TNF‑α. The mRNA expression and protein levels of OPG were upregulated, and ALP activity was increased. These findings suggested that Lenti‑siTNFα‑OPG transfection inhibited the wear particle‑induced inflammatory response and osteoclastogenesis, which warrants further investigation for the prevention and/or treatment of wear particle-induced osteolysis.

Topics: Animals; Cell Line; DNA, Complementary; Gene Expression Regulation, Developmental; Gene Silencing; Humans; Inflammation; Lentivirus; Mice; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; RNA, Small Interfering; Titanium; Transfection; Tumor Necrosis Factor-alpha

This study aimed to assess the effect of multiple sessions of a low-level laser therapy (LLLT) adjuvant to scaling and root planing (SRP) on the treatment of experimental periodontitis (EP) in rats treated with 5-fluorouracil (5-FU).. A total of 120 rats were divided into five groups: no treatment (NT); treatment with 5-FU (60 and 40 mg/kg) and no local periodontal treatment (5FU); treatment with 5-FU and SRP (5FU-SRP); treatment with 5-FU, SRP and one LLLT session (660 nm; 0.035 W; 4.2 J; 120 s) (5FU-SRP-1LLLT); and treatment with 5-FU, SRP and four LLLT sessions (0, 24, 48 and 72 h) (5FU-SRP-4LLLT). EP was induced in the mandibular molars through ligature placement. The alveolar bone loss (ABL) area in the furcation region was analysed histometrically. TRAP, proliferating cell nuclear antigen, RANKL, osteoprotegerin and activated caspase-3 patterns were analysed by immunolabeling. Prostaglandin E2 was quantified using an ELISA, and tumour necrosis factor α and interleukin-6 were assessed using the multiplex method. The prevalence rates of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella nigrescens, Prevotella intermedia and Fusobacterium nucleatum were assessed using the PCR method. The data were subjected to statistical analysis (α = 5%).. 5FU, 5FU-SRP and 5FU-SRP-1LLLT treatment groups showed higher ABL compared with the NT group (p < 0.05), whereas the 5FU-SRP-4LLLT group showed lower ABL compared with the 5FU group on day 7 and decreased RANKL immunolabeling (p < 0.05).. Treatment with 5-FU worsened EP, and multiple LLLT sessions adjuvant to SRP seemed to improve periodontitis in rats subjected to 5-FU chemotherapy.

Topics: Alveolar Bone Loss; Animals; Bacteria; Caspase 3; Combined Modality Therapy; Dental Scaling; Dinoprostone; Drug Therapy; Fluorouracil; Inflammation; Interleukin-6; Low-Level Light Therapy; Male; Mandible; Molar; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Root Planing; Tumor Necrosis Factor-alpha

To determine mechanisms involved in endothelial dysfunction (ED) during the course of arthritis and to investigate the link between cytokines, chemokines and osteoprotegerin.. Experiments were conducted on aortic rings at day 4 (preclinical), day 11 (onset of disease), day 33 (acute disease) and day 90 (chronic disease) after adjuvant-induced arthritis (AIA) in Lewis rats. At day 4, the unique vascular abnormality was a reduced norepinephrine-induced constriction. At day 11, endothelial function assessed by the relaxation to acetylcholine was normal despite increased cyclo-oxygenase-2 activity (COX-2) and overproduction of superoxide anions that was compensated by increased nitric oxide synthase (NOS) activity. At day 33, ED apparition coincides with the normalization of NOS activity. At day 90, ED was only observed in rats with a persisting imbalance between endothelial NOS and COX-2 pathways and higher plasma levels of IL-1β and TNFα. Plasma levels of IL-1β, TNFα and MIP-1α negatively correlated with Ach-induced relaxation throughout the course of AIA.. Our data identified increased endothelial NOS activity as an important compensatory response that opposes the ED in the early arthritis. Thereafter, a cross-talk between endothelial COX-2/NOS pathways appears as an important element for the occurrence of ED. Our results encourage determining the clinical value of IL-1β, TNFα and MIP-1α as biomarkers of ED in RA.

Topics: Acetylcholine; Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Biomarkers; Chemokines; Cyclic N-Oxides; Cyclooxygenase 2; Disease Progression; Endothelium, Vascular; Immunization; Inflammation; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase Type III; Nitrobenzenes; Nitroprusside; Osteoprotegerin; Radiography; Rats, Inbred Lew; Spin Labels; Sulfonamides; Superoxides; Time Factors; Vasoconstriction; Vasodilation

Inflammation and immune activation have been implicated in the pathophysiology of severe mental disorders. Previous studies of inflammatory markers, however, have been limited with somewhat inconsistent results.. We aimed to determine the effect sizes of inflammatory marker alterations across diagnostic groups of the psychosis continuum and investigate association to antipsychotic medications.. Plasma levels of soluble tumor necrosis factor receptor 1 (sTNF-R1), interleukin 1 receptor antagonist (IL-1Ra), osteoprotegerin (OPG), and von Willebrand factor (vWf) were measured in patients (n=992) with schizophrenia spectrum (SCZ, n=584), schizoaffective disorder (SA, n=93), affective spectrum disorders (AFF, n=315), and healthy controls (HC, n=638).. Levels of sTNF-R1 (p=1.8×10(-8), d=0.23) and IL-1Ra (p=0.002, d=0.16) were increased in patients compared to HC. The SCZ group had higher levels of sTNF-R1 (p=8.5×10(-8), d=0.27) and IL-1Ra (p=5.9×10(-5), d=0.25) compared to HC, and for sTNF-R1 this was also seen in the SA group (p=0.01, d=0.3) and in the AFF group (p=0.002, d=0.12). Further, IL-1Ra (p=0.004, d=0.25) and vWf (p=0.02, d=0.21) were increased in the SCZ compared to the AFF group. There was no significant association between inflammatory markers and use of antipsychotic medication.. We demonstrate a small increase in sTNF-R1 and IL-1Ra in patients with severe mental disorders supporting a role of inflammatory mechanisms in disease pathophysiology. The increase was more pronounced in SCZ compared to AFF supporting a continuum psychosis model related to immune factors.

Topics: Adult; Antipsychotic Agents; Biomarkers; Case-Control Studies; Female; Humans; Inflammation; Interleukin 1 Receptor Antagonist Protein; Male; Models, Psychological; Mood Disorders; Osteoprotegerin; Psychotic Disorders; Psychotropic Drugs; Receptors, Tumor Necrosis Factor, Type I; Schizophrenia; von Willebrand Factor; Young Adult

To investigate the correlation of serum osteoprotegerin (OPG) with the progression of nonalcoholic fatty liver disease (NAFLD) and the noninvasive prediction and diagnosis of nonalcoholic steatohepatitis (NASH).. A total of 136 patients with NAFLD were enrolled, and their tissue samples for liver biopsy and serum samples obtained at 1 week after liver biopsy were collected; 83 healthy subjects without the symptoms of fatty liver disease proved by ultrasound examination were enrolled as controls. The physiological indicators including height, body weight, and waist circumference were measured, and body mass index was calculated. The biochemical parameters including alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ALT, alkaline phosphatase, gamma-glutamyl transferase, total cholesterol, triglyceride (TG), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured. Double-antibody sandwich enzyme-linked immunosorbent assay was used to determine the serum level of OPG. The rank sum test, chi-square test, t-test, one-way analysis of variance, Spearman correlation analysis, least significant difference test, and receiver operating characteristic (ROC) curve were applied for statistical analysis of various data.. Serum OPG level was correlated with AST and TG (P < 0.05), and was highly correlated with hepatocyte fatty degeneration, ballooning degeneration, intralobular inflammation, portal inflammation, and fibrosis degree (P < 0.01). With the increasing NAFLD activity score (NAS), serum OPG level decreased, and there was a highly negative correlation between them (r = -0.928, P < 0.01). Serum OPG level was significantly lower in NASH patients than non-NASH patients. The area under the ROC curve of serum OPG level was 0.963, and according to the Youden index, its optimal sensitivity and specificity were 96.1% and 97.4%, respectively, at an optimal cut-off value of 242.96 ng/L, which suggested a high diagnostic power.. In NASH patients, serum OPG level decreases significantly. Serum OPG level can be used as an independent predictive factor to evaluate NASH and its severity, as well as a noninvasive diagnostic index for NASH.

Topics: Alanine Transaminase; Alkaline Phosphatase; Aspartate Aminotransferases; Biopsy; Body Mass Index; Case-Control Studies; Cholesterol; Disease Progression; Enzyme-Linked Immunosorbent Assay; Fibrosis; gamma-Glutamyltransferase; Humans; Inflammation; Liver; Non-alcoholic Fatty Liver Disease; Osteoprotegerin; ROC Curve; Triglycerides

Vascular injury and dysfunction contribute to cardiovascular disease, the leading cause of death in patients with chronic kidney disease (CKD). Osteoprotegerin (OPG) is a soluble member of the tumor necrosis factor receptor superfamily that has been linked to atherogenesis and endothelial dysfunction. Elevated circulating OPG levels predict future cardiovascular events (CVE). Our aim was to evaluate the determinants of circulating OPG levels, to investigate the relationship between OPG and markers of vascular damage and to test whether OPG improves risk stratification for future CVE beyond traditional and renal-specific risk factors in a CKD population. 291 patients with CKD stage 1-5 not on dialysis were included in the study. In the multivariate analysis, OPG was a significant predictor for flow-mediated dilatation, but not for carotid intima media thickness levels. During follow-up (median 36 months, IQR = 32-42 months), 87 patients had CVE. In the Cox survival analysis, OPG levels were independently associated with CVE even after adjustment for traditional and renal-specific cardiovascular risk factors. The addition of OPG to a model based on commonly used cardiovascular factors significantly improved the reclassification abilities of the model for predicting CVE. We show for the first time that OPG improves risk stratification for CVE in a non-dialysis CKD population, above and beyond a model with established traditional and renal-specific cardiovascular risk factors, including estimated glomerular filtration rate and fibroblast growth factor 23.

Topics: Adult; Aged; Atherosclerosis; Cardiovascular Diseases; Carotid Intima-Media Thickness; Female; Glomerular Filtration Rate; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; Renal Insufficiency, Chronic; Risk Factors

Chronic inflammatory processes in periapical tissues caused by etiological agents of endodontic origin lead to apical periodontitis. Apart from bacteria, two herpesviruses, Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) are recognized as putative pathogens in apical periodontitis. Although previous reports suggest the involvement of EBV in the pathogenesis of apical periodontitis, its exact role in periapical bone resorption has not yet been fully elucidated. We hypothesize that EBV infection in apical periodontitis is capable of inducing periapical bone resorption via stimulation of reactive oxygen species (ROS) overproduction. Increased levels of ROS induce expression of receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL). RANKL binding to receptor activator of nuclear factor κB (RANK) present on the surface of preosteoclasts induces their maturation and activation which consequently leads to bone resorption. The potential benefit of antiviral and antioxidant-based therapies in periapical bone resorption treatment remains to be assessed.

Topics: Animals; B-Lymphocytes; Bone Resorption; Epithelial Cells; Epstein-Barr Virus Infections; Herpesvirus 4, Human; Humans; Inflammation; Models, Theoretical; Osteoclasts; Osteoprotegerin; Periapical Periodontitis; RANK Ligand; Reactive Oxygen Species; Receptor Activator of Nuclear Factor-kappa B

To study the expression and possible role of OPG/RANK/RANKLin the rat dental pulp of periodontitis combined with vascular calcification.. Thirty-six male Wister rats were randomly divided into 4 groups: control group(group C), periodontitis group(group CP), vascular calcification group(group VDN) and compound group(group CP+VDN). Each group underwent corresponding management to establish animal model. When the model was successful, the maxillae including molars were sectioned, pulp tissue was examined by H-E staining; Immunohistochemical staining method was used to evaluate the expression and ratio of OPG and RANKL in pulp tissues. Statistical analysis was carried out using SPSS 19.0 software package.. The pulp tissue of group CP, VDN, CP+VDN showed varied degrees of damage, neutrophil infiltration, pulp vascular congestion, odontoblasts vacuolar changes, pulp necrosis by H-E staining, and the changes in CP+VDN group was the most significant, followed by CP group, VDN group. Immunohistochemistry showed OPG in pulp tissues in group CP, VDN, CP+VDN were significantly lower than that in normal group (P<0.05), and the expression in group CP+VDN was the least;Expression of RANKL in pulp tissues in group CP, VDN, CP+VDN were significantly higher than that in normal group(P<0.05)，and the expression in group CP+VDN was the highest. The ratio of OPG/RANKL in normal group was the highest, and the ratio in CP+VDN group was the lowest.. Periodontitis and vascular calcification can damage the pulp tissue, periodontitis compound with vascular calcification may aggravate the injury; OPG/RANKL/RANK system may play an important role in pulp tissue injury.

Topics: Animals; Dental Pulp; Disease Models, Animal; Immunohistochemistry; Inflammation; Male; Molar; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Vascular Calcification

Interleukin-33 (IL-33) controls T-helper type 2 (Th2) cytokines and the development of mast cells. This study aimed to investigate the expression of IL-33 and its association with RANKL and osteoprotegerin (OPG) in periodontal health and experimental periodontitis.. Eighteen Wistar rats were assigned to two study groups of nine animals each: ligature only (LO) and nonligated (NL). Silk sutures were placed subgingivally, surrounding the right lower first molars. The animals were killed on day 11 after ligature placement, and the alveolar bone loss at the first molars was determined histometrically. Periodontal tissues were examined histopathologically to evaluate the differences between the groups. The expression of IL-33, RANKL and OPG was detected immunohistochemically.. The LO group showed significantly greater alveolar bone loss compared with the NL group (p < 0.05). The numbers of osteoclasts, osteoblasts and inflammatory cells were significantly higher in the LO group compared with the NL group (p < 0.05). Osteoblastic activity was significantly lower in the LO group than in the NL group (p < 0.05). There was significantly higher expression of IL-33 and RANKL and a greater number of OPG-positive cells in the LO group (p < 0.05). IL-33 expression showed a positive correlation with RANKL expression and with the number of mast cells (p < 0.05).. The experimental periodontitis group exhibited increased expression of IL-33 and RANKL compared with the healthy group. Additionally, there was a positive correlation between these expressions. According to these results, IL-33 could be associated with the pathogenesis of periodontal disease.

Topics: Alveolar Bone Loss; Animals; Cell Count; Inflammation; Interleukin-33; Mast Cells; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Sutures

The aim of the study was to evaluate and compare faecal markers of intestinal inflammation in children with cystic fibrosis (CF), and determine whether intestinal inflammation adversely affects the nutritional phenotype.. Faecal samples for markers of intestinal inflammation, calprotectin, S100A12, and osteoprotegerin, were collected from children with CF, healthy controls (HCs), and Crohn disease (CD). Associations between inflammatory markers and clinical and nutritional indices were determined in subjects with CF.. Twenty-eight children with CF (mean [standard deviation (SD)] 8.4 [3.3] years old, 22 pancreatic insufficient [PI]), 47 HC, and 30 CD were recruited. Mean (SD) faecal calprotectin in CF (94.3 [100.6] mg/kg) was greater than HC (26.7 [15.4] mg/kg, P < 0.0001), but lower than CD (2133 [2781] mg/kg, P = 0.0003). Abnormal faecal calprotectin was found in subjects only with PI (17/22 (77%), P = 0.001). There was no difference in faecal mean (SD) S100A12 (0.8 [0.9] vs 1.5 [2.2] mg/kg, P = 0.14) and osteoprotegerin concentrations (72.7 [52.2] vs 62.5 [0.0] pg/mL, P = 0.2) between CF and HC. Patients with CD had significantly elevated S100A12 and osteoprotegerin compared with CF and HC. Faecal calprotectin inversely correlated with both weight (r = -0.5, P = 0.003) and height z scores (r = -0.6, P = 0.002) in CF.. The pattern of intestinal inflammation in CF is unique and distinct from inflammatory bowel disease, with elevated faecal calprotectin but normal faecal S100A12 and osteoprotegerin concentrations. The severity of intestinal inflammation, based on faecal calprotectin, significantly correlates with poor growth.

Topics: Adolescent; Biomarkers; Child; Child, Preschool; Crohn Disease; Cystic Fibrosis; Enzyme-Linked Immunosorbent Assay; Exocrine Pancreatic Insufficiency; Feces; Female; Growth; Growth Disorders; Humans; Inflammation; Intestinal Mucosa; Leukocyte L1 Antigen Complex; Male; Osteoprotegerin; S100A12 Protein

Receptor-activator of NF-κB, its ligand RANKL, and the soluble decoy receptor osteoprotegerin are the key regulators of osteoclast differentiation and bone remodeling. Although there is a strong association between osteoporosis and skeletal muscle atrophy/dysfunction, the functional relevance of a particular biological pathway that synchronously regulates bone and skeletal muscle physiopathology still is elusive. Here, we show that muscle cells can produce and secrete osteoprotegerin and pharmacologic treatment of dystrophic mdx mice with recombinant osteoprotegerin muscles. (Recombinant osteoprotegerin-Fc mitigates the loss of muscle force in a dose-dependent manner and preserves muscle integrity, particularly in fast-twitch extensor digitorum longus.) Our data identify osteoprotegerin as a novel protector of muscle integrity, and it potentially represents a new therapeutic avenue for both muscular diseases and osteoporosis.

Topics: Animals; Cell Line; Immunoglobulin Fc Fragments; In Vitro Techniques; Inflammation; Leukocytes; Lipopolysaccharides; Male; Mice, Inbred C57BL; Muscle Fibers, Skeletal; Muscles; Muscular Dystrophy, Animal; Osteoprotegerin

The objective of the study was to determine the relationship between common carotid artery intima-media thickness (CCA-IMT) and histologically assessed calcification of radial artery in relation to clinical features and laboratory markers of bone and mineral metabolism, inflammation, and oxidative stress in patients with stage 5 chronic kidney disease (CKD).. The study comprised 59 patients (36 hemodialyzed, 23 predialysis). CCA-IMT was measured by ultrasonography; the biochemical parameters examined were assessed using routine laboratory methods, ELISA micro-plate immunoassays and spectrophotometry. Fragments of radial artery obtained during creation of hemodialysis access were cryosectioned and stained for calcifications using von Kossa method and alizarin red.. Glucose, osteoprotegerin, pentraxin 3 and Framingham risk score significantly correlated with CCA-IMT. In multiple regression analysis, OPG positively predicted CCA-IMT. Radial artery calcifications were found in 34 patients who showed higher CCA-IMT (0.98 ± 0.13 vs 0.86 ± 0.14 mm; P = 0.006). Higher CCA-IMT values were also associated with more advanced calcifications. CCA-IMT and the presence of plaques in common carotid artery were positive predictors of radial artery calcifications, independent of dialysis status, Framingham risk score, CRP and Ca x Pi [OR for calcifications 2.19 (1.08-4.45) per 0.1 mm increase in CCA-IMT]. The presence of radial artery calcifications was a significant predictor of mortality, independent of dialysis status and Framingham risk score [HR 3.16 (1.03-9.64)].. In CKD patients, CCA-IMT examination can be used as a surrogate measure to assess the incidence and severity of arterial medial calcification which is associated with poor clinical outcome in these patients.

Topics: Adult; Aged; Aged, 80 and over; alpha-2-HS-Glycoprotein; Blood Glucose; C-Reactive Protein; Cardiovascular Diseases; Carotid Artery, Common; Carotid Intima-Media Thickness; Cohort Studies; Coronary Artery Disease; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Incidence; Inflammation; Insulin Resistance; Interleukin-6; Kidney Failure, Chronic; Logistic Models; Middle Aged; Multivariate Analysis; Osteocalcin; Osteopontin; Osteoprotegerin; Oxidative Stress; Radial Artery; Renal Dialysis; Renal Insufficiency, Chronic; Risk Assessment; Serum Amyloid P-Component; Severity of Illness Index; Tunica Media; Vascular Calcification

Topics: Cystic Fibrosis; Female; Growth; Humans; Inflammation; Intestinal Mucosa; Leukocyte L1 Antigen Complex; Male; Osteoprotegerin; S100A12 Protein

Periprosthetic osteolysis, involving RANK/RANKL/osteoprotegerin (OPG) and TNF-α/NFκB signaling, contributes to bone resorption and inflammation. We constructed lentivirus vectors to inhibit TNF-α and enhance OPG expression and assessed their impacts on wear debris-induced inflammation and osteoclastogenesis in an osteoclast/osteoblast coculture system.. We transduced mouse osteoblastic MC3T3-E1 cells with Lenti-negative control (Lenti-NC), Lenti-OPG or Lenti-siTNFα-OPG, and murine macrophage/monocyte RAW264.7 cells with Lenti-NC, Lenti-TNF-α siRNA or Lenti-siTNFα-OPG. Then, TNF-α and OPG protein levels were evaluated by enzyme-linked immunosorbent assay. We cocultured transduced MC3T3-E1 and RAW264.7 cells in transwell chambers in the presence of 0.1 mg/mL Ti particles to investigate the capacity of TNF-α inhibition to reduce wear debris-induced inflammation. We also assessed mRNA levels TNF-α, IL-1β, IL-6 and OPG by RT-PCR as well as osteoclastogenesis by tartrate-resistant acid phosphatase.. Lenti-siTNFα-OPG ameliorated Ti-particle-induced expression of TNF-α, IL-1β, IL-6 in MC3T3-E1/RAW264.7 cocultures, while enhancing mRNA and protein levels of OPG, and reducing the fraction of tartrate-resistant acid phosphatase (TRAP)+ cells.. Lenti-siTNFα-OPG can inhibit the wear debris-induced inflammatory responses and osteoclastogenesis in vitro, and may represent a promising therapeutic candidate for the treatment or prevention of wear particle-induced osteolysis.

Topics: Animals; Cytokines; Inflammation; Mice; Osteoclasts; Osteolysis; Osteoprotegerin; Tumor Necrosis Factor-alpha

Abdominal aortic calcification (AC) has been reported to be associated with cardiovascular disease (CVD) in hemodialysis patients but is rarely discussed in peritoneal dialysis (PD) patients. We examined the independent predictors and predictive power for survival of AC in prevalent PD patients.. AC was detected by computed tomography (CT) and represented as the percentage of the total aortic cross-section area affected by AC (%AC). The predictors of %AC ≥ 15 were examined by multiple logistic regression analysis. Cox proportional hazard analysis was used to determine the hazard ratios associated with high %AC. A total of 183 PD patients were recruited to receive CT scans and divided into group 1 (%AC < 15, n = 97), group 2 (%AC ≥ 15, n = 41), and group 3 (diabetic patients, n = 45). Group 1 patients had lower osteoprotegerin (OPG) levels than group 2 patients (798 ± 378 vs. 1308 ± 1350 pg/mL, p < 0.05). The independent predictors for %AC ≥ 15 included the atherogenic index, OPG, and C-reactive protein (CRP). The age-adjusted hazard ratios associated with %AC ≥ 15 were 3.46 (p = 0.043) for mortality and 1.90 (p = 0.007) for hospitalization.. %AC can predict mortality and morbidity in non-diabetic PD patients, and 15% is a good cut-off value for such predictions. There are complex associations among mineral metabolism, inflammation, and dyslipidemia in the pathogenesis of AC.

Topics: Adult; Aged; Aorta, Abdominal; Biomarkers; C-Reactive Protein; Calcinosis; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus; Dyslipidemias; Female; Follow-Up Studies; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; Peritoneal Dialysis; Prospective Studies; Taiwan; Tomography, X-Ray Computed

To investigate the effects of ginsenoside metabolite compound K (CK) on adjuvant-induced arthritis (AA) rats and the partial mechanisms focused on the function of immunocyte (B cell and macrophage) and effectors' cell (fibroblast-like synoviocyte, FLS).. Animals were divided randomly into nine groups including control, AA, CK (5, 10, 20, 40, 80, and 160 mg/kg, i.g.), and MTX (0.5 mg/kg, i.g.). The effects of CK on AA rats are evaluated by swelling of the paw, histopathology of joint, and inflammatory cytokine production in serum. To further investigate the effects of CK on the function of B cell, peritoneal macrophage, and FLS from AA rats, we examined the proliferation of B cell and FLS by [3H] thymidine incorporation, and the phagocytic function of peritoneal macrophage was measured by neutral red uptake. Cytokines and antibodies in serum and the supernatant from peritoneal macrophage and FLS were measured by ELISA kit.. CK suppressed the severity of AA rats by attenuating the paw swelling and histopathology of joint. CK can inhibit the proliferation of B cell and autoantibody levels, and suppressed the phagocytic function of peritoneal macrophage and secreted pro-inflammatory cytokines TNF-α, IFN-γ, and IL-17 and up-regulated the level of protective cytokines IL-10. CK attenuated the proliferation of FLS, and balanced the ratio of RANKL to OPG in AA rats.. Our results suggest that CK may attenuate the severity of AA rats, partially by influencing the function of immunocyte (B cell and macrophage) and effectors' cells (FLS) in AA.

Topics: Animals; Arthritis, Experimental; B-Lymphocytes; Cell Proliferation; Ginsenosides; Inflammation; Interferon-gamma; Interleukin-10; Interleukin-17; Macrophages, Peritoneal; Male; Osteoprotegerin; RANK Ligand; Rats; Rats, Sprague-Dawley; Synovial Membrane; Tumor Necrosis Factor-alpha

This study evaluated the alveolar bone response to testosterone and the impact of Resolvin D2 (RvD2) on testosterone-induced osteoblast function. For the in vivo characterization, 60 male adult rats were used. Treatments established sub-physiologic (L), normal (N), or supra-physiologic (H) concentrations of testosterone. Forty rats were subjected to orchiectomy; 20 rats received periodical testosterone injections while 20 rats received testicular sham-operation. Four weeks after the surgeries, 10 rats in each group received a subgingival ligature around the lower first molars to induce experimental periodontal inflammation and bone loss. In parallel, osteoblasts were differentiated from neonatal mice calvariae and treated with various doses of testosterone for 48 h. Cell lysates and conditioned media were used for the determination of alkaline phosphatase, osteocalcin, RANKL, and osteoprotegerin. Micro-computed tomography linear analysis demonstrated that bone loss was significantly increased for both L and H groups compared to animals with normal levels of testosterone. Gingival IL-1β expression was increased in the L group (p<0.05). Ten nM testosterone significantly decreased osteocalcin, RANKL, and OPG levels in osteoblasts; 100 nM significantly increased the RANKL:OPG ratio. RvD2 partially reversed the impact of 10 nM testosterone on osteocalcin, RANKL, and OPG. These findings suggest that both L and H testosterone levels increase inflammatory bone loss in male rats. While low testosterone predominantly increases the inflammatory response, high testosterone promotes a higher osteoblast-derived RANKL:OPG ratio. The proresolving mediator RvD2 ameliorates testosterone-derived downregulation of osteocalcin, RANKL, and OPG in primary murine osteoblasts suggesting a direct role of inflammation in osteoblast function.

Topics: Alkaline Phosphatase; Animals; Bone and Bones; Cells, Cultured; Cytokines; Docosahexaenoic Acids; Down-Regulation; Inflammation; Male; Mice; Osteoblasts; Osteocalcin; Osteoprotegerin; Periodontal Diseases; RANK Ligand; Rats; Testosterone; X-Ray Microtomography

The interleukin-1 receptor antagonist (IL-1Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is not clear whether IL-1Ra plays a protective role in periodontal disease. This study was undertaken to compare experimental periodontitis induced by Aggregatibacter actinomycetemcomitans in IL-1Ra knockout (KO) mice and wild-type (WT) mice. Computed tomography (CT) analysis and hematoxylin-and-eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were performed. In addition, osteoblasts were isolated; the mRNA expression of relevant genes was assessed by real-time quantitative PCR (qPCR); and calcification was detected by Alizarin Red staining. Infected IL-1Ra KO mice exhibited elevated (P, <0.05) levels of antibody against A. actinomycetemcomitans, bone loss in furcation areas, and alveolar fenestrations. Moreover, protein for tumor necrosis factor alpha (TNF-α) and IL-6, mRNA for macrophage colony-stimulating factor (M-CSF), and receptor activator of NF-κB ligand (RANKL) in IL-1Ra KO mouse osteoblasts stimulated with A. actinomycetemcomitans were increased (P, <0.05) compared to in WT mice. Alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN)/bone gla protein (BGP), and runt-related gene 2 (Runx2) mRNA levels were decreased (P, <0.05). IL-1α mRNA expression was increased, and calcification was not observed, in IL-1 Ra KO mouse osteoblasts. In brief, IL-1Ra deficiency promoted the expression of inflammatory cytokines beyond IL-1 and altered the expression of genes involved in bone resorption in A. actinomycetemcomitans-infected osteoblasts. Alterations consistent with rapid bone loss in infected IL-Ra KO mice were also observed for genes expressed in bone formation and calcification. In short, these data suggest that IL-1Ra may serve as a potential therapeutic drug for periodontal disease.

Topics: Aggregatibacter actinomycetemcomitans; Animals; Bone Diseases, Metabolic; Bone Resorption; Gene Expression Regulation; Inflammation; Interleukin 1 Receptor Antagonist Protein; Macrophage Colony-Stimulating Factor; Mice; Mice, Knockout; Osteoprotegerin; Pasteurellaceae Infections; Periodontitis; RANK Ligand

Pentraxin-3 (PTX3), also known as tumor necrosis factor-stimulated gene 14 (TSG-14), is produced by immune and vascular cells in response to pro-inflammatory signals and is therefore a multipotent inflammatory mediator. The present study showed that during human osteoblast (OB) differentiation, precursor OBs (pOBs), but not mature OB, highly expressed PTX3. TNFα treatment elevated the PTX3 expression of pOBs. When mice were injected with lipopolysaccharide, which induces an inflammatory osteolytic condition characterized by trabecular bone destruction and high osteoclastogenesis, their bone marrow cells expressed elevated levels of PTX3 protein. Exogenous PTX3 did not directly affect osteoclast (OC) or OB differentiation. However, when pOBs and precursor OCs were co-cultured, exogenous PTX3 significantly increased the number of tartrate-resistant acid phosphatase-positive multinucleated cells (i.e., OC cells) by increasing the pOB mRNA expression and protein secretion of RANK ligand (RANKL). This was accompanied with increased Runt-related transcription factor 2 (Runx2) expression in the pOBs. Knock-down of endogenous PTX3 with small-interfering RNA did not change the osteogenic potential of pOBs but suppressed their production of RANKL and reduced osteoclastogenesis. Finally, TNFα treatment of the co-culture elevated PTX3 expression by the pOBs and increased OC formation. This effect was suppressed by PTX3 knock-down by decreasing RANKL expression. Thus, the PTX3-driven increase in the osteoclastogenic potential of pOBs appears to be mediated by the effect of PTX3 on pOB RANKL production. These findings suggest that PTX3 is an inflammatory mediator that contributes to the deteriorating osteolytic condition of inflamed bone. J. Cell. Physiol. 229: 1744-1752, 2014. © 2014 Wiley Periodicals, Inc.

Topics: Animals; Bone Marrow Cells; C-Reactive Protein; Cell Differentiation; Coculture Techniques; Gene Knockdown Techniques; Humans; Inflammation; Mice; Mice, Inbred ICR; Nerve Tissue Proteins; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Serum Amyloid P-Component; Solubility; Tumor Necrosis Factor-alpha

To investigate diet and nutrition-related factors associated with bone loss in a group of postmenopausal (PM) women. Nutritional intake, inflammatory markers and body composition (weight, body mass index, fat/lean mass) were analysed for associations with bone mineral density (BMD).. A cross sectional study examining correlations between BMD (Duel-energy X ray absorptiometry; (DXA) and dietary intake (3-day diaries), body composition and plasma bone and inflammatory markers: C-terminal telopeptide of type I collagen (CTX) and procollagen type I N propeptide (P1NP), C- reactive protein (CRP), interleukin 6 and 10 (IL-6, IL-10), tumour necrosis factor (TNF) and osteoprotegerin (OPG).. Community dwelling women from the Auckland, Hawke's Bay and Manawatu regions in New Zealand.. 142 healthy, PM women aged 50-70 years.. OPG (per kilogram fat mass) was increased in women with osteoporosis (p<0.001) compared to groups classified with normal BMD and osteopenia. Protein, vitamin B12, zinc, potassium and dairy intake were all positively correlated with higher BMD while dairy and potassium intakes also inversely correlated with CTX. Body composition (weight, BMI and fat/lean mass) had strong positive associations with BMD. Multiple regression analysis showed body weight, potassium and dairy intake were predictors of increased BMD in PM women and explained 39% (r2=0.39, p< 0.003) of variance.. BMD was negatively correlated with OPG and positively with weight, dairy and potassium intake. This study highlights the importance of maintaining adequate body weight and emphasising dairy and potassium predominantly sourced from fruit/vegetables to reduce bone loss at midlife.

Topics: Absorptiometry, Photon; Aged; Body Composition; Body Mass Index; Body Weight; Bone Density; Bone Diseases, Metabolic; C-Reactive Protein; Collagen Type I; Cross-Sectional Studies; Cytokines; Dairy Products; Diet; Dietary Proteins; Female; Health; Humans; Inflammation; Interleukin-10; Interleukin-6; Middle Aged; New Zealand; Osteoporosis, Postmenopausal; Osteoprotegerin; Peptide Fragments; Peptides; Postmenopause; Potassium; Procollagen; Tumor Necrosis Factor-alpha; Vitamin B 12; Zinc

Inflammation is believed to link obesity to insulin resistance, as in the setting of metabolic syndrome (MetS). Osteoprotegerin (OPG) is a soluble protein that seems to exert proatherogenic and prodiabetogenic effects. This study aims at determining OPG levels in MetS and whether OPG might contribute to MetS development and progression.. Circulating OPG was measured in 46 patients with MetS and 63 controls, and was found significantly elevated in those with MetS. In addition, circulating and tissue OPG was significantly increased in high-fat diet (HFD) fed C57BL6 mice, which is one of the animal models for the study of MetS. To evaluate the consequences of OPG elevation, we delivered this protein to C57BL6 mice, finding that it promoted systemic and adipose tissue proinflammatory changes in association with metabolic abnormalities.. These data suggest that OPG may trigger adipose tissue proinflammatory changes in MetS/HFD-induced obesity.

Topics: Adipose Tissue; Adult; Animals; Blood Glucose; Body Mass Index; C-Reactive Protein; Case-Control Studies; Cholesterol, HDL; Cholesterol, LDL; Diet, High-Fat; Female; Humans; Inflammation; Insulin; Insulin Resistance; Male; Metabolic Syndrome; Mice; Mice, Inbred C57BL; Middle Aged; Obesity; Osteoprotegerin; Triglycerides

A number of studies have suggested that angiotensin II (AII) receptor type 1 (ATR1) blocking drugs (ARBs) have anti-inflammatory effects however the mechanisms responsible are poorly investigated.. To determine the role of extracellular signal regulated kinase (ERK)1/2 in ARB induced anti-inflammatory effects within human carotid atherosclerosis.. Atheroma samples obtained from patients undergoing carotid endarterectomy were cultured with and without ATR1 (irbesartan), ERK1/2 (PD98059), AII ([Sar(1), Ile(8)]-AII) and angiotensin converting enzyme (ACE)2 (DX600) blockade. The in vitro effects of ATR1 and ERK1/2 blockade and exogenous AII on serum stimulated healthy, primary vascular cells were also investigated. Outcome was assessed by measuring cytokine, (interleukin (IL)-6, IL-8, C-C motif chemokine (CCL)2, C-X-C motif chemokine (CXCL)5, osteoprotegerin (OPG), osteopontin (OPN), CXCL16), concentrations in supernatants and phosphorylated ERK1/2 in the tissue lysates using ELISA. ERK1/2 expression in the tissue was assessed using Western blotting.. Irbesartan reduced concentrations of IL-6, IL-8, CCL2, CXCL5, OPG, OPN and CXCL16 in both atheroma and primary vascular cell culture supernatants. The reduction in cytokine levels in the atheroma supernatant was correlated to a reduction in ERK1/2 expression in the tissue. Inhibition of ERK1/2 downregulated IL-6, IL-8 and CXCL5 in both atheroma and cell culture supernatants. AII and ACE2 blockade had no impact on cytokine or active ERK1/2 levels in the atheroma culture.. Our findings suggest that ATR1 blockade downregulates atheroma tissue ERK1/2 expression leading to a reduction in cytokine production and that a non-AII agonist ATR1 signalling response may induce expression of these inflammation associated cytokines in the atheroma.

Topics: 1-Sarcosine-8-Isoleucine Angiotensin II; Aged; Angiotensin II Type 1 Receptor Blockers; Biphenyl Compounds; Carotid Arteries; Cells, Cultured; Chemokines; Cytokines; Endothelium, Vascular; Enzyme Activation; Enzyme Induction; Female; Humans; Inflammation; Irbesartan; Male; MAP Kinase Signaling System; Middle Aged; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Osteoprotegerin; Peptides; Plaque, Atherosclerotic; Renin-Angiotensin System; Tetrazoles

The dental pulp space can become infected due to a breach in the surrounding hard tissues. This leads to inflammation of the pulp (pulpitis), soft tissue breakdown, and finally to bone loss around the root apex (apical periodontitis). The succession of the molecular events leading to apical periodontitis is currently not known. The main inflammatory mediator associated with neutrophil chemotaxis is interleukin-8 (IL-8), and with bone resorption the dyad of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG). The levels of RANKL, OPG and IL-8 were studied in periapical tissue fluid of human teeth (n = 48) diagnosed with symptomatic irreversible pulpitis (SIP) and asymptomatic apical periodontitis (AAP). SIP represents the starting point, and AAP an established steady state of the disease. Periapical tissue fluid samples were collected using paper points and then evaluated using enzyme-linked immunosorbent assays (ELISAs). Target protein levels per case were calibrated against the corresponding total protein content, as determined fluorometrically. RANKL was expressed at significantly higher levels in SIP compared to AAP (P < 0.05), whereas OPG was under the detection limit in most samples. In contrast, IL-8 levels were significantly lower in SIP compared to AAP (P < 0.05). Spearman's correlation analysis between RANKL and IL-8 revealed a significantly (P < 0.05) negative correlation between the two measures (rho = -.44). The results of this study suggest that, in the development of apical periodontitis, periapical bone resorption signaling, as determined by RANKL, occurs prior to inflammatory cell recruitment signaling, as determined by IL-8.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bone Resorption; Dental Pulp; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation; Interleukin-8; Male; Middle Aged; Osteoprotegerin; Periapical Periodontitis; Periapical Tissue; Pulpitis; RANK Ligand; Young Adult

Wear-particle-induced osteolysis is considered to be the main reason for revision after arthroplasty. Although the exact mechanism remains unclear, inflammatory osteoclastogenesis plays an important role in this process. Strontium ranelate (SR) was found to have a therapeutic effect on osteoporosis in postmenopausal women. Based on prior studies, the present authors hypothesized that SR prevents wear-particle-induced osteolysis through restraining inflammatory osteoclastogenesis. The present study used 80 male C57BL/J6 mice to test this hypothesis in a murine osteolysis model. All experimental animals were randomly divided into four groups: a control group; a SR group; a titanium group; and a titanium+SR group. Once titanium particles had been implanted in mice, the mice were administered SR (900 mg kg(-1) day(-1)) by gavage for 14 days. After 14 days, the calvaria were collected for micro-computed tomography (μCT), histological and molecular analysis. The results of μCT and histomorphometric analysis demonstrated that SR markedly inhibited bone resorption and the generation of tartrate-resistant acid-phosphatase-positive cells in vivo, compared with titanium-stimulated calvaria. Reverse transcription polymerase chain reaction and ELISAs showed that SR stimulated the mRNA and protein expression of osteoprotegerin, and inhibited gene and protein expression of receptor activators of nuclear factor-kappa B ligand in titanium-particle-charged calvaria. In addition, SR obviously reduced the secretion of tumor necrosis factor-α and interleukin-1β in the calvaria of the titanium group. It was concluded that SR inhibits titanium-induced osteolysis by restraining inflammatory osteoclastogenesis, and that it could be developed as a new drug to prevent and treat aseptic loosening.

Topics: Acid Phosphatase; Animals; Inflammation; Interleukin-1beta; Isoenzymes; Male; Mice, Inbred C57BL; Osteoclasts; Osteogenesis; Osteolysis; Osteoprotegerin; RANK Ligand; RNA, Messenger; Skull; Staining and Labeling; Tartrate-Resistant Acid Phosphatase; Thiophenes; Titanium; Tumor Necrosis Factor-alpha; X-Ray Microtomography

Inflammation plays a significant role in the pathogenesis of pulmonary arterial hypertension (PAH). Soluble receptor activator of nuclear factor-ĸB ligand (sRANKL) and osteoprotegerin (OPG) are tumor necrosis factor α family members of immunomodulatory activity.. The aim of the study was to evaluate sRANKL and OPG concentrations in patients with PAH as potential factors contributing to the development of the disease.. We studied 26 patients with PAH, 31 volunteers, and 24 stable patients with chronic systolic left ventricular heart failure (LVHF) without pulmonary hypertension. The PAH group was followed up for 6 months for clinical deterioration or death.. sRANKL levels were higher in the PAH group compared with controls and the LVHF group (5.6 [interquartile range, 3.9-7.9) vs. 2.0 [0.9-4.4] pmol/l; P = 0.0001, and 2.4 [1.3-4.2] pmol/l; P = 0.001, respectively). OPG levels were higher in PAH patients compared with controls (4.07 ±1.9 vs. 3.27 ±0.95 pmol/l; P = 0.048). We found significant correlations between sRANKL levels and parameters of ventilatory efficiency during exercise in the PAH group. OPG levels correlated with brain natriuretic peptide levels and with invasive hemodynamic parameters. Patients with clinical deterioration during 6-month follow-up (n = 9) showed higher baseline OPG levels compared with stable patients (n = 17, 5.09 ±2.6 vs. 3.52 ±1.19 pmol/l; P = 0.043). In the univariate analysis, the elevated OPG concentration at baseline was associated with an increased risk and earlier occurrence of clinical deterioration (hazard ratio, 1.43; 95% confidence interval, 1.06-1.9; P = 0.017).. Concentrations of sRANKL and OPG are elevated in patients with PAH and are associated with indicators of disease severity and prognosis. sRANKL is a better discriminant between PAH and LVHF than OPG. The baseline OPG concentration is significantly associated with adverse outcomes in patients with PAH.

Topics: Biomarkers; Female; Humans; Hypertension, Pulmonary; Inflammation; Male; Osteoprotegerin

To study the effect of Bushen Tongdu Capsule (BTC) on RANK/RANKL/ OPG pathway of collagen induced arthritis (CIA) rats, thereby laying theoretic evidence for treating rheumatic arthritis (RA) by Chinese medicine.. RA model was induced by CIA. Totally 42 rats were randomly divided into six groups, i.e., the normal control group, the model group, the low dose BTC (BSL) group, the medium dose BTC (BSM) group, the high dose BTC (BSH) group, and the Tripterygium Glycosides (TG) group, 7 in each group. BTC at the daily dose of 120, 240, and 480 mg/kg was given by gastrogavage to rats in the BSL, BSM, and BSH group respectively from the 13th day of modeling. TG at the daily dose of 24 mg/kg was given by gastrogavage to rats in the TG group. All medication was given once daily, 2 mL each time. Two mL normal saline was administered to rats in the normal control group and the model group. All medication lasted for 18 days. Samples were taken at day 31. The TRAP section of the ankle joint was fixed in 10% formalin for TRAP stain. Serum levels of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), and macrophage colony-stimulating factor (M-CSF) were detected using ELISA.. Compared with the normal control group, positive reactions of pathological ankle joint section, inflammation, and osteoclasia degree were significantly improved in the model group, serum levels of RANKL and M-CSF were up-regulated, levels of OPG and OPG/RANKL were significantly lowered (all P < 0.01). Compared with the model group, positive reactions of pathological ankle joint section, inflammation, and osteoclasia degree also significantly decreased in the BSH group and the TG group (all P < 0.01). RANKL and M-CSF were significantly down-regulated in each medicated group, while levels of OPG and OPG/RANKL were significantly up-regulated (all P < 0.01). Compared with the TG group, M-CSF was lower, but levels of OPG and OPG/RANKL were significantly up-regulated in the normal control group (all P < 0.01). RANKL and M-CSF were significantly up-regulated, while levels of OPG and OPG/RANKL were significantly down-regulated in the model group and each BS group (all P < 0.01).. BTC could relieve bone damage of CIA rats possibly through regulating and controlling osteoclasts.

Topics: Animals; Arthritis, Experimental; Drugs, Chinese Herbal; Inflammation; Macrophage Colony-Stimulating Factor; Osteoclasts; Osteoprotegerin; RANK Ligand; Rats; Receptor Activator of Nuclear Factor-kappa B; Tripterygium

Traditional clinical risk factors are associated with inflammation cross-sectionally, but associations of longitudinal variation in inflammatory biomarkers with corresponding changes in clinical risk factors are incompletely described. We sought to analyze clinical factors associated with change in inflammation in the community.. We studied 3013 Framingham Offspring (n = 2735) and Omni Cohort (n = 278) participants (mean age 59 years, 55% women, 9% ethnic/racial minority) who attended two consecutive examination cycles (mean 6.7 years apart). We selected ten inflammatory biomarkers representing distinctive biological functions: C-reactive protein (CRP), intercellular adhesion molecule-1, interleukin-6, isoprostanes, lipoprotein-associated phospholipase-2 (Lp-PLA2) activity, Lp-PLA2-mass, monocyte chemoattractant protein-1, osteoprotegerin, P-selectin, and tumor necrosis factor receptor II (TNFRII). We constructed multivariable-adjusted regression models to assess the relations of baseline, follow-up and change in clinical risk factors with change in biomarker concentrations over time.. Baseline, follow-up and change in clinical risk factors explain a moderate amount of the variation in biomarker concentrations across 2 consecutive examinations (ranging from r(2) = 0.28 [TNFRII] up to 0.52 [Lp-PLA2-mass]). In multivariable models, increasing body-mass index, smoking initiation, worsening lipid profile, and increasing waist size were associated with increasing concentrations of several biomarkers. Conversely, hypercholesterolemia therapy and hormone replacement cessation were associated with decreasing concentrations of biomarkers such as CRP, Lp-PLA2-mass and activity.. Cardiovascular risk factors have different patterns of association with longitudinal change in inflammatory biomarkers and explain modest amounts of variability in biomarker concentrations. Nevertheless, a substantial proportion of longitudinal change in inflammatory markers is not explained by traditional risk factors.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Aged; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Chemokine CCL2; Female; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-6; Isoprostanes; Longitudinal Studies; Male; Massachusetts; Middle Aged; Osteoprotegerin; P-Selectin; Receptors, Tumor Necrosis Factor, Type II; Risk Factors; Vasculitis

To investigate and compare the expression of the pathogen recognition receptors Toll-like receptor (TLR) 2 and TLR4, and the hard tissue resorption triad osteoprotegerin (OPG)-receptor activator of nuclear factor kappa-B ligand (RANKL)-receptor activator of nuclear factor kappa-B (RANK) in external inflammatory root resorption of endodontic origin (ER) and external cervical root resorption (ECR) by immunohistochemistry.. Formalin-fixed, paraffin-embedded archival specimens collected from teeth that were diagnosed clinically, radiographically and histopathologically with either ER (n = 9) or ECR (n = 9) were processed for immunohistochemistry to investigate and compare levels of TLR2, TLR4, OPG, RANKL, RANK, CD3, CD19 and CD83 expression. The histological features were evaluated via haematoxylin and eosin stain. Taylor's modification of the Brown and Brenn Gram stain was used for examining the presence and distribution of bacteria. All stained slides were digitally photographed and qualitatively analysed, and F test and unpaired Student's t-test were used for statistical analysis.. Both ER and ECR showed similar immuno-histopathology characteristics of a fibrovascular connective tissue with varying degrees of inflammatory infiltrate consisting of T and B lymphocytes, dendritic cells, polymorphonuclear lymphocytes and plasma cells. Colonies of bacteria were identified in the majority of lesions, and this correlated with the cellular expression of TLR2 and TLR4 in all lesions. Similarly, all lesions showed a significantly higher (P < 0.05) level of cells expressing RANKL than OPG, indicating hard tissue resorption processes where active in the lesions.. The immunohistopathology patterns of ECR samples were consistent with the bacteria-driven ER specimens, suggesting bacteria-induced inflammation may be involved in ECR.

Topics: Humans; Inflammation; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Root Resorption; Toll-Like Receptor 2; Toll-Like Receptor 4; Tooth Cervix

Osteoprotegerin (OPG), a soluble member of the tumor necrosis factor (TNF) receptor super-family, is a key factor inhibiting the differentiation and activation of osteoclasts. It has recently been implicated as a disease marker for inflammatory bowel disease (IBD) yet its role in the intestinal epithelial inflammatory response remains unknown.. The primary objective of this study was to investigate whether OPG has a role in intestinal inflammation and a potential role in IBD pathogenesis.. Caco-2 and HT-29 cells were grown in vitro to confluence on culture-permeable supports and then co-cultured with either TNF-α or OPG. After exposure to either TNF-α or OPG, interleukin (IL)-8 protein and mRNA levels were evaluated. Ussing chamber, western blotting, real-time polymerase chain reaction, and immunofluorescence were used to further investigate the effect of OPG on intestinal barrier integrity and function.. Similar to TNF-α, treatment of monolayers with OPG caused increased monolayer permeability and diminished tight junction function and integrity, with loss of tight junction proteins from cell membranes. This was accompanied by elevated IL-8 protein and gene levels (P < 0.05). Western blotting also revealed that OPG, similar to TNF-α, induced NF-κB activation, as shown by inhibition of NF-κB kinase subunit-α phosphorylation.. These results indicate that OPG has pro-inflammatory properties because it induces gut barrier dysfunction and secretion of other pro-inflammatory cytokines. These results also provide evidence that OPG is likely to exert its pro-inflammatory effects through NF-κB activation and may potently contribute to IBD pathogenesis.

Topics: Caco-2 Cells; Cell Survival; Gene Expression Regulation; HT29 Cells; Humans; Inflammation; Interleukin-6; NF-kappa B; Osteoprotegerin; Tumor Necrosis Factor-alpha

This study investigated the efficacy of a combination gene therapy to repress interleukin-1 (IL-1) and receptor activator of nuclear factor NF-kappa B ligand (RANKL) for the treatment of particulate debris-induced aseptic loosening, and tried to explore the molecular mechanism of the exogenous gene modifications on osteoclastogenesis. RAW cells activated by titanium particles were transduced with DFG-IL-1Ra (retroviral vector encoding IL-1 receptor antagonist) and AAV-OPG (adeno-associated viral vectors-osteoprotegerin) individually or in combination for 4 weeks. Pro-inflammatory cytokines in culture media were determined by enzyme-linked immunosorbent assay, and gene expressions of RANK, IL-1β, c-Fos, TRAF6, JNK1 and CPK were examined using real-time PCR. An established knee-implant-failure mouse model was employed to evaluate the efficacy of the in vivo double-gene therapy. The surgical implantation of a titanium alloy pin into the proximal tibia was followed by monthly challenge with titanium debris. Peri-implant gene transfers of IL-1Ra and OPG (respectively or in combination) were given 3 weeks after surgery. The combination of OPG and IL-1Ra gene transfer exhibited strong synergetic effects in blockage of inflammation and osteoclastogenesis at 8 weeks after gene modification. The combination therapy reversed peri-implant bone resorption and restored implant stability when compared with either single gene transduction. Real-time PCR data indicated that the action of IL-1Ra gene therapy may be mediated via the JNK1 pathway, while the reduction of osteoclastogenesis by OPG gene modification may be regulated by c-Fos expression. In addition, both gene modifications resulted in significant diminishment of TRAF6 expression.

Topics: Animals; Bone Regeneration; Bone Resorption; Cell Differentiation; Cell Line, Tumor; Genetic Therapy; Implants, Experimental; Inflammation; Interleukin 1 Receptor Antagonist Protein; Interleukin-1beta; Knee Prosthesis; Mice; Mice, Inbred BALB C; Osteoclasts; Osteoprotegerin; Prosthesis Failure; RANK Ligand; Titanium

Hyperglycemia occurs in patients with poorly controlled diabetes mellitus and contributes to bone resorption and increased susceptibility to bacterial infections. Hyperglycemia can incite low-grade inflammation that can contribute to the resorption of bone, especially the periodontal bone. The increased susceptibility to periodontal infections can contribute to bone resorption through the activation of osteoclasts. In this study, the osteoblastic, clonal cell line, MC3T3-E1, was used in an in vitro model of hyperglycemia and lipopolysaccharide-induced reactive oxygen species generation to determine the potential anti-inflammatory effect of 635 nm light-emitting diode (LED) irradiation or whether 635 nm LED irradiation can be a potential anti-inflammatory treatment. LED irradiation of MC3T3-E1 cells stimulated with lipopolysaccharide in a high glucose-containing medium decreased the level of cyclooxygenase gene and protein expression and reduced the level of prostaglandin E2 expression by decreasing the amount of reactive oxygen species generation. LED irradiation also inhibited the osteoclastogenesis in MC3T3-E1 cells by regulating the receptor activator of nuclear factor kappa-B ligand and osteoprotegerin. These findings reveal the mechanisms which are important in the pathogenesis of diabetic periodontitis and highlight the beneficial effects of 635 nm LED irradiation in reducing the adverse effects of diabetic periodontitis.

Topics: 3T3 Cells; Animals; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Gene Expression; Glucose; Hyperglycemia; Inflammation; Inflammation Mediators; Light; Lipopolysaccharides; Membrane Proteins; Mice; Osteoblasts; Osteoprotegerin; Phototherapy; RANK Ligand; Reactive Oxygen Species

Recent data have demonstrated the importance of IL-18 in the induction and perpetuation of chronic inflammation in experimental arthritis. The aim of the present study was to elucidate whether IL-18 has any indirect effects on osteoclastogenesis by regulating the production of molecules from fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA). Human FLS were isolated from RA synovial tissue and cultured in vitro for three to five passages. The expression of IL-18 receptor was determined by RT-PCR. The levels of soluble receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), macrophage colony-stimulating factor (M-CSF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in culture supernatants were determined by ELISA. Membrane-bound RANKL expression was analyzed by flow cytometry. Both α and β chains of IL-18 receptor were confirmed in cultured FLS. IL-18 upregulated membrane-bound RANKL expression and soluble RANKL production by FLS in both time- and dose-dependent manners. In addition, IL-18 enhanced production of M-CSF, GM-CSF, and OPG from cultured FLS in a dose-dependent manner. IL-18 also increased the ratio of RANKL/OPG, suggesting that the net effect of IL-18 on FLS favors for the induction of osteoclast formation and bone resorption. In conclusion, IL-18 upregulates the production of key regulators of osteoclastogenesis from FLS in RA.

Topics: Arthritis, Rheumatoid; Bone Resorption; Cells, Cultured; Female; Gene Expression; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Inflammation; Interleukin-18; Interleukin-18 Receptor alpha Subunit; Interleukin-18 Receptor beta Subunit; Macrophage Colony-Stimulating Factor; Middle Aged; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Synovial Membrane; Up-Regulation

Experimental and clinical data suggest that statins may protect bone by inhibiting bone resorption and/or stimulating bone formation. Interleukin-6 (IL-6) is produced by osteoblasts, and potently stimulates osteoclast activation playing a key role in normal bone resorption as well as in post-menopausal and inflammation-driven osteoporosis. Although statins inhibit IL-6 production from different cell types, currently no data exist on osteoblasts. The aim of the study was to evaluate the effect of rosuvastatin on IL-6 production by human osteoblasts.. Osteoblasts from osteoarthritic patients were incubated with rosuvastatin (0.1-10 μmol/L)±IL-1β, and IL-6 production was evaluated as cytokine concentration in the culture medium (ELISA), as well as mRNA expression in the cells (qPCR). Putative intracellular mechanisms of the drug, such as blocking HMG-CoA-reductase, and interference in the prenylation process were investigated by the addition of mevalonate and isoprenoids. The effect of rosuvastatin±IL-1β on the anti-resorptive molecule osteoprotegerin (OPG) was also assessed (ELISA).. Rosuvastatin significantly reduced IL-6 levels in the osteoblast culture medium, both in unstimulated and IL-1β-stimulated cells. This effect was reversed by mevalonate or geranylgeraniol, but not farnesol. Moreover, the drug decreased both spontaneous and IL-1β-induced IL-6 mRNA expression in osteoblasts. Conversely, rosuvastatin did not affect OPG levels in the culture medium.. Our results show that rosuvastatin decreases IL-6 production by osteoblasts, thereby suggesting a possible inhibiting activity on osteoclast function in an indirect way. These data may provide further rationale for employing rosuvastatin to beneficially affect bone metabolism in post-menopausal women and possibly in inflammation-driven osteoporosis.

Topics: Aged; Bone Resorption; Cell Proliferation; Cell Survival; Cells, Cultured; Culture Media; Diterpenes; Farnesol; Femur Head; Fluorobenzenes; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Inflammation; Interleukin-1beta; Interleukin-6; Mevalonic Acid; Middle Aged; Osteoblasts; Osteoporosis; Osteoprotegerin; Pyrimidines; RNA, Messenger; Rosuvastatin Calcium; Sulfonamides; Terpenes

Pro-inflammatory cytokines possess osteoclastogenic or anti-osteoclastogenic activities. They influence osteoclasts directly or via the receptor activator of nuclear factor κB (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG) system. Recent evidence suggests that inflammation may play a role in osteoporosis (OP) and osteoarthritis (OA). We aimed therefore to determine whether there is a difference between both groups: first, in the expression of the osteoclastogenic and anti-osteoclastogenic cytokines, second, in correlation of these cytokines with bone mineral density (BMD) and levels of bone turnover markers (BTM) and third, in correlation between the expression of these cytokines and osteoclast specific genes and RANK/RANKL/OPG genes.. Human bone samples from 54 age and sex matched patients with OP or OA were collected during hip arthroplasty surgery. The expression of 25 genes encoding pro-inflammatory cytokines, their receptors, osteoclast specific genes and RANK/RANKL/OPG genes was measured using quantitative real-time PCR. Total hip, femoral neck and lumbar spine BMD and BTM in blood samples were measured. The comparison between OP and OA was assessed using Student's t-test or Mann-Whitney U test and correlations between gene expression, BMD and BTM were determined using nonparametric correlation.. The results demonstrated a higher expression of interleukin (IL)-6 and IL-1α in OP, and interferon (IFN)-γ in OA (p < 0.0005). Negative correlations of total hip BMD with tumor necrosis factor-α (TNF-α) in OA and with RANKL/RANK in OP were found (p < 0.05). Significant correlations with BTM were shown for IL-1α and IFN-γ in OP (rho = 0.608 and -0.634) and for TNF-α, IL-6 and transforming growth factor-β1 (TGF-β1) in OA (rho = 0.591, -0.521 and 0.636). Results showed OP specific negative correlations (IFN-γ with ITGB3, IFN-β1 with CTSK, tartrate resistant acid phosphatase (TRAP), CALCR, RANK, RANKL, IL-1α with CTSK, OPG, IL-17A with CALCR) and positive (TGF-β1 with CTSK, TRAP, RANK), and OA specific negative (IL-1α with osteoclast associated immunoglobulin-like receptor (OSCAR), TNF-α with RANK, RANKL, OPG) and positive (IL-6 with RANK, RANKL, OPG) correlations.. Our results demonstrate that the relationship between osteoclastogenic and anti-osteoclastogenic pro-inflammatory cytokines differs in human OP and OA bone and could present an important factor for characteristics of OP and OA bone phenotypes.

Topics: Aged; Arthroplasty; Bone Density; Cytokines; Female; Gene Expression Regulation; Humans; Inflammation; Male; Osteoarthritis; Osteoclasts; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytokine

In hemodialysis patients, 25-hydroxyvitamin D conversion to active 1,25-dihydroxyvitamin D by the kidneys is very limited. The expression of both vitamin D receptor and 1alpha-hydroxylase in cells of the immune system and in both osteoblasts and osteoclasts makes it possible that 25-hydroxyvitamin D could play an important role in both inflammation and bone metabolism acting in a autocrine and/or paracrine way in these patients.. Thirty-three hemodialysis patients not under vitamin D receptor agonist treatment were enrolled into the study. Serum levels of 25-hydroxyvitamin D, C-reactive protein (CRP), interleukin-6 (IL-6), receptor activator of nuclear factor-kappaB ligand (RANKL), and osteoprotegerin, as well as intact parathyroid hormone were assessed by immunoassays.. Regarding inflammation, 25-hydroxyvitamin D inversely correlated with both CRP and IL-6. Regarding bone metabolism, 25-hydroxyvitamin D was positively related to osteoprotegerin, but negatively to the RANKL. The latter could be the result of parathyroid hormone suppression by 25-hydroxyvitamin D, since 25-hydroxyvitamin D negatively correlated with parathyroid hormone, which in turn was positively related to RANKL.. Serum 25-hydroxyvitamin D is inversely correlated with markers of inflammation and may suppress osteoclastic activity in hemodialysis patients.

Topics: Biomarkers; Bone Resorption; C-Reactive Protein; Female; Humans; Inflammation; Interleukin-6; Kidney Failure, Chronic; Male; Middle Aged; Osteoclasts; Osteoprotegerin; Parathyroid Hormone; RANK Ligand; Renal Dialysis; Vitamin D

Wear particle-induced vascularized granulomatous inflammation and subsequent inflammatory osteolysis is the most common cause of aseptic loosening after total joint replacement (TJR); however, the precise mechanism by which this occurs is unclear. This study investigates the effects of the proteasome inhibitor bortezomib (Bzb) on the expression of key biochemical markers of bone metabolism and vascularised granulomatous tissues, such as receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), vascular endothelial growth factor (VEGF) and tumor necrosis factor receptor-associated factor 6 (TRAF6). In addition, the effect of Bzb on apoptosis of CD68+ cells was examined. A total of 32 female BALB/C mice were randomly divided into four groups. After implantation of calvaria bone from syngeneic littermates, titanium (Ti) particles were injected into established air pouches for all mice (excluding negative controls) to provoke inflammatory osteolysis. Subsequently, Bzb was administered at a ratio of 0, 0.1, or 0.5 mg/kg on day 1, 4, 8, and 11 post-surgery to alleviate this response. All of the air pouches were harvested 14 days after the surgical procedure and were processed for molecular and histological analysis. The results demonstrated that Ti injection elevated the expression of RANKL, OPG, VEGF, and TRAF6 at both the gene and protein levels, increased counts of infiltrated cells and thickness of air pouch membranes, and elevated the apoptosis index (AI) of CD68+ cells. Bzb treatment significantly improved Ti particle-induced implanted bone osteolysis, attenuated vascularised granulomatous tissues and elevated AI of CD68+ cells. Therefore, the proteasome pathway may represent an effective therapeutic target for the prevention and treatment of aseptic loosening.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Apoptosis; Arthroplasty, Replacement; Boronic Acids; Bortezomib; Female; Inflammation; Mice; Mice, Inbred BALB C; Osteolysis; Osteoprotegerin; Prosthesis Failure; Proteasome Inhibitors; Pyrazines; Random Allocation; RANK Ligand; Titanium; TNF Receptor-Associated Factor 6; Vascular Endothelial Growth Factors

Since ingredients of peri-implant sulcus fluid (PISF) may be related to the bony structure surrounding dental implants, analyze of specific markers related to bone resorption in PISF seems to be suitable for long term monitoring of peri-implant health. It is suggested that analysis of PISF may serve for detection of inflammation. The aim of this study is to analyze PISF interleukin-1 beta (IL-1β), IL-10, osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B ligand (RANKL) levels to determine whether the diagnostic value of PISF can be used to evaluate early changes around implants.. A total of 47 dental implants either healthy/non-inflamed (n=20) (Group I), or gingivitis/inflamed (n=27) (Group II), were classified. Peri-implant status has been evaluated by clinical evaluation (plaque index, gingival index, probing depth and gingival bleeding time index) were recorded and PISF samples were also obtained. PISF IL-1β, IL-10, RANKL, and OPG levels were measured by enzyme-linked immunosorbent assay. Potential volumetric changes in PISF were also evaluated.. All clinical parameters and volume of PISF were higher in Group II and these differences were statistically significant except volume values. IL-1β, IL-10 and OPG levels in PISF were significantly higher in Group II. Although the PISF RANKL level in Group II was higher than the level of Group I, the difference between groups did not reach the statistically significant level.. These data suggest that a balance of inflammatory- and osteoclastogenesis related molecules locally produced may play an important role in the development of inflammatory peri-implant lesions.

Topics: Adult; Aged; Biomarkers; Body Fluids; Bone Remodeling; Cytokines; Dental Implants; Female; Humans; Inflammation; Interleukin-10; Interleukin-1beta; Male; Middle Aged; Osteoprotegerin; RANK Ligand

In our study, we explored the bidirectional communication via soluble factors between bone cells and endotoxin-stimulated splenic lymphocytes in an in vitro coculture model that mimics the inflammatory environment. Both the ability of lymphocytes to affect differentiation and immune properties of bone cells, osteoblasts (OBL) and osteoclasts (OCL), and of bone cells to modulate cytokine and activation profile of endotoxin-stimulated lymphocytes were tested. LPS-pulsed lymphocytes enhanced OCL but inhibited OBL differentiation and increased the RANKL/OPG ratio, and, at the same time, upregulated chemotactic properties of bone cells, specifically CCL2, CCL5, and CXCL10 in OCL and CCL5 and CXCL13 in OBL. In parallel, bone cells had immunosuppressive effects by downregulating the lymphocyte expression of interleukin (IL)-1, IL-6, TNF-α and co-stimulatory molecules. OCL stimulated the production of osteoclastogenic cytokine RANKL in T lymphocytes. The anti-inflammatory effect, especially of OBL, suggests a possible compensatory mechanism to limit the inflammatory reaction during infection.

Topics: Animals; Bone Marrow Cells; Cell Differentiation; Cells, Cultured; Chemokine CCL2; Chemokine CCL5; Chemokine CXCL10; Chemokine CXCL13; Female; Inflammation; Interleukin-1; Interleukin-6; Lipopolysaccharides; Lymphocyte Activation; Lymphocytes; Mice; Mice, Inbred C57BL; Osteoblasts; Osteoclasts; Osteoprotegerin; RANK Ligand; Tumor Necrosis Factor-alpha; Up-Regulation

Inflammatory biomarkers are reported as risk factors for atrial fibrillation (AF), but their impact is uncertain.. We investigated the associations between inflammatory biomarkers and future AF in a large general cohort.. Available markers were white blood cells (WBCs) with subgroups, fibrinogen, high-sensitivity C-reactive protein (hs-CRP), and osteoprotegerin (OPG). A total of 6315 men and women from a population survey in Tromsø, Norway in 1994 to 1995 were followed for a mean of 10.9 years. Mean age at baseline was 60 years. Measurements of height, weight, blood pressure, heart rate, total cholesterol, high-density lipoprotein (HDL) cholesterol, WBC count, and information on diabetes, angina, myocardial infarction, and antihypertensive treatment, were obtained at baseline. Fibrinogen, hs-CRP, and OPG were obtained at a follow-up visit. The outcome measure was first-ever AF, documented on an electrocardiogram. The Cox proportional hazards regression model was used to estimate hazard ratios of AF.. In the multivariable analysis, adjusted for traditional cardiovascular risk factors and other inflammatory biomarkers, hs-CRP was associated with AF in men only (hazard ratio = 1.14 for a 1 SD increase; 95% CI, 1.02-1.28). There was a significant increase in AF across quartiles of WBCs in men (P = 0.007) and in the total study population (P = 0.004). OPG was associated with AF in patients free of coronary heart disease at baseline. Fibrinogen and subgroups of WBCs showed no significant association with AF.. This population-based cohort study showed that hs-CRP was independently associated with AF in men, but apparently not in women, and that patients with WBCs in the upper quartile had increased risk of AF.

Topics: Adult; Aged; Aged, 80 and over; Atrial Fibrillation; Biomarkers; C-Reactive Protein; Coronary Disease; Electrocardiography; Female; Fibrinogen; Humans; Inflammation; Leukocyte Count; Male; Middle Aged; Multivariate Analysis; Norway; Osteoprotegerin; Proportional Hazards Models; Prospective Studies; Risk Factors; Sex Factors

Osteoprotegerin (OPG), as an osteoclast antagonist, limits mineralised tissue resorption under physiological conditions. Previous work investigating OPG in a rat periodontal ligament (PDL) ankylosis model found no inhibitory effect on osteoclasts when OPG was administered at a dosage of 2.5mg/kg.. The object of this study was to determine whether dosages higher than 2.5 mg/kg of OPG were required to limit osteoclastic activity in an aseptic inflammatory model in rats.. Dry ice was applied for 15 minutes to the upper right first molar crown of eighteen, 8-week-old, male Sprague-Dawley rats. Three groups of 3 were injected with OPG at dosages of 2.5, 5.0 and 7.5 mg/kg of body weight immediately following the thermal insult. After 7 days, the rats were sacrificed and each maxilla processed for histological examination and stained for osteoclastic activity using tartrate-resistant acid phosphatase (TRAP). Osteoclast population numbers were estimated via light microscopy and results were analysed using a comparative mixed model statistical analysis.. Results showed OPG inhibited osteoclastic activity in a dose-dependent manner. From 2.5 mg/kg to 7.5 mg/kg, osteoclast populations were linearly reduced by 39.78% (p < 0.05). OPG did not appear to affect the inflammatory process and had varied efficacy in different regions of individual teeth.. Although osteoclastic activity reduced, it was not completely eliminated, perhaps because dosages were still inadequate, or additional factors might influence OPG and osteoclast activation in the aseptic inflammatory model.

Topics: Acid Phosphatase; Animals; Biomarkers; Cell Count; Disease Models, Animal; Dose-Response Relationship, Drug; Dry Ice; Freezing; Inflammation; Isoenzymes; Male; Maxilla; Molar; Necrosis; Odontoblasts; Osteoclasts; Osteoprotegerin; Rats; Rats, Sprague-Dawley; Root Resorption; Tartrate-Resistant Acid Phosphatase; Tooth Crown

Porphyromonas gingivalis is an oral pathogen highly implicated in chronic periodontitis, a disease characterized by inflammatory destruction of the tooth-supporting alveolar bone and eventually, tooth loss. T-cell innate immune responses are actively involved in this pathological process. Receptor activator of NF-κB Ligand (RANKL) is a cytokine that stimulates bone resorption, while its soluble decoy receptor osteoprotegerin (OPG) blocks its action. This study aimed to investigate in Jurkat T-cells the effects of P. gingivalis on the RANKL-OPG system and the major inflammatory mediator of bone resorption prostaglandin E(2) (PGE(2)). P. gingivalis caused concentration-dependent up-regulation of RANKL gene expression and protein production, assessed by quantitative PCR and ELISA, respectively. PGE(2) production was also enhanced. However, OPG was not detected. In conclusion, P. gingivalis induces RANKL and PGE(2) in T-cells, potentially favoring bone resorption. These T-cell responses to P. gingivalis may contribute to the pathogenesis of inflammatory alveolar bone destruction occurring in chronic periodontitis.

Topics: Bone Resorption; Dinoprostone; Enzyme-Linked Immunosorbent Assay; Gene Expression; Humans; Inflammation; Jurkat Cells; NF-kappa B; Osteoprotegerin; Polymerase Chain Reaction; Porphyromonas gingivalis; RANK Ligand; T-Lymphocytes

Bone-lining tissues contain a population of resident macrophages termed osteomacs that interact with osteoblasts in vivo and control mineralization in vitro. The role of osteomacs in bone repair was investigated using a mouse tibial bone injury model that heals primarily through intramembranous ossification and progresses through all major phases of stabilized fracture repair. Immunohistochemical studies revealed that at least two macrophage populations, F4/80(+) Mac-2(-/low) TRACP(-) osteomacs and F4/80(+) Mac-2(hi) TRACP(-) inflammatory macrophages, were present within the bone injury site and persisted throughout the healing time course. In vivo depletion of osteomacs/macrophages (either using the Mafia transgenic mouse model or clodronate liposome delivery) or osteoclasts (recombinant osteoprotegerin treatment) established that osteomacs were required for deposition of collagen type 1(+) (CT1(+)) matrix and bone mineralization in the tibial injury model, as assessed by quantitative immunohistology and micro-computed tomography. Conversely, administration of the macrophage growth factor colony-stimulating factor 1 (CSF-1) increased the number of osteomacs/macrophages at the injury site significantly with a concurrent increase in new CT1(+) matrix deposition and enhanced mineralization. This study establishes osteomacs as participants in intramembranous bone healing and as targets for primary anabolic bone therapies.

Topics: Acid Phosphatase; Animals; Bone Matrix; Calcification, Physiologic; Clodronic Acid; Disease Models, Animal; Inflammation; Isoenzymes; Liposomes; Macrophage Colony-Stimulating Factor; Macrophages; Membranes; Mice; Mice, Inbred C57BL; Mice, Transgenic; Osteoblasts; Osteogenesis; Osteoprotegerin; Surface Properties; Tartrate-Resistant Acid Phosphatase; Tibia; Wound Healing

Fracture healing is orchestrated by a specific set of events that culminates in the repair of bone and reachievement of its biomechanical properties. The aim of our work was to study the sequence of gene expression events involved in inflammation and bone remodeling occurring in the early phases of callus formation in osteoporotic patients.. Fifty-six patients submitted to hip replacement surgery after a low-energy hip fracture were enrolled in this study. The patients were grouped according to the time interval between fracture and surgery: bone collected within 3 days after fracture (n = 13); between the 4(th) and 7(th) day (n = 33); and after one week from the fracture (n = 10). Inflammation- and bone metabolism-related genes were assessed at the fracture site. The expression of pro-inflammatory cytokines was increased in the first days after fracture. The genes responsible for bone formation and resorption were upregulated one week after fracture. The increase in RANKL expression occurred just before that, between the 4(th)-7(th) days after fracture. Sclerostin expression diminished during the first days after fracture.. The expression of inflammation-related genes, especially IL-6, is highest at the very first days after fracture but from day 4 onwards there is a shift towards bone remodeling genes, suggesting that the inflammatory phase triggers bone healing. We propose that an initial inflammatory stimulus and a decrease in sclerostin-related effects are the key components in fracture healing. In osteoporotic patients, cellular machinery seems to adequately react to the inflammatory stimulus, therefore local promotion of these events might constitute a promising medical intervention to accelerate fracture healing.

Topics: Adaptor Proteins, Signal Transducing; Aged, 80 and over; Bone Morphogenetic Proteins; Bone Remodeling; Bony Callus; Down-Regulation; Female; Fracture Healing; Genetic Markers; Hip Fractures; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Male; Osteocytes; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Up-Regulation

The role of fat-bone interactions in the pathogenesis of osteoporosis in chronic obstructive pulmonary disease (COPD) is poorly understood. Our aim was to investigate expressions of leptin and osteoprotegerin (OPG) in the adipose tissue, and their relationships to osteoporosis in patients with COPD.. In 39 patients with stable COPD, bone mineral density (BMD) and body composition was assessed by Dual Energy X-Ray Absorptiometry. Serum leptin was determined by the enzyme-linked immunosorbent assay, and bone turnover markers osteocalcin and β-crosslaps by the electrochemiluminiscence immunoassays. Subcutaneous adipose tissue samples were analyzed using real-time PCR.. Twenty-one patients without, and 18 with osteoporosis were enrolled (35 men; age 62.2 ± 7.3years). Compared to patients without osteoporosis, those with the disease had significantly lower serum levels and adipose tissue expressions of leptin, in association with increased serum β-crosslaps (p=0.028, p=0.034, p=0.022, respectively). Log adipose tissue leptin was inversely related to serum β-crosslaps (p=0.015), and directly to serum leptin (p<0.001) and to the total, femoral, and lumbar BMD and T-score (p<0.02 for all relationships). Adipose tissue OPG expression was related to all variables of bone density except for lumbar BMD and T-score (p<0.05 for all relationships). Log adipose tissue leptin and OPG expressions predicted femoral T-score independently of age, gender and pulmonary function (p<0.001, adjusted R(2)=0.383; p=0.008, adjusted R(2)=0.301, respectively). Introducing body mass (or fat mass) index into these models eliminated independent predictive value of leptin and OPG expressions.. Our results suggest that adipose tissue leptin and OPG expressions are related to osteoporosis in patients with COPD, and appear to act as mediators between fat mass and BMD.

Topics: Adipose Tissue; Biomarkers; Bone Density; Bone Remodeling; Female; Humans; Inflammation; Leptin; Male; Middle Aged; Osteoporosis; Osteoprotegerin; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests

There is a tight interaction of the bone and the immune system. However, little is known about the relevance of the complement system, an important part of innate immunity and a crucial trigger for inflammation. The aim of this study was, therefore, to investigate the presence and function of complement in bone cells including osteoblasts, mesenchymal stem cells (MSC), and osteoclasts. qRT-PCR and immunostaining revealed that the central complement receptors C3aR and C5aR, complement C3 and C5, and membrane-bound regulatory proteins CD46, CD55, and CD59 were expressed in human MSC, osteoblasts, and osteoclasts. Furthermore, osteoblasts and particularly osteoclasts were able to activate complement by cleaving C5 to its active form C5a as measured by ELISA. Both C3a and C5a alone were unable to trigger the release of inflammatory cytokines interleukin (IL)-6 and IL-8 from osteoblasts. However, co-stimulation with the pro-inflammatory cytokine IL-1β significantly induced IL-6 and IL-8 expression as well as the expression of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) indicating that complement may modulate the inflammatory response of osteoblastic cells in a pro-inflammatory environment as well as osteoblast-osteoclast interaction. While C3a and C5a did not affect osteogenic differentiation, osteoclastogenesis was significantly induced even in the absence of RANKL and macrophage-colony stimulating factor (M-CSF) suggesting that complement could directly regulate osteoclast formation. It can therefore be proposed that complement may enhance the inflammatory response of osteoblasts and increase osteoclast formation, particularly in a pro-inflammatory environment, for example, during bone healing or in inflammatory bone disorders.

Topics: Adult; Antigens, CD; Cell Differentiation; Cells, Cultured; Complement C3a; Complement C5a; Gene Expression; Humans; Inflammation; Interleukin-1beta; Male; Mesenchymal Stem Cells; Microscopy, Fluorescence; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; Proteolysis; RANK Ligand; Receptors, Complement; Young Adult

Elevated levels of inflammation are reported in bipolar disorders (BP), but how this relates to affective symptoms is unclear. We aimed to determine if immune markers that consistently have been reported elevated in BP were associated with depressive and manic symptoms, and if this was specific for BP.. From a catchment area, 112 BP patients were included together with 153 schizophrenia (SCZ) patients and 239 healthy controls. Depression and mania were assessed and the patients were grouped into depressed, neutral, and elevated mood. We measured the immune markers tumor necrosis factor receptor 1 (sTNF-R1), interleukin 1 receptor antagonist (IL-1Ra), interleukin 6 (IL-6), high sensitive C-reactive protein (hsCRP), osteoprotegerin (OPG) and von Willebrand factor (vWf) which have been found increased in severe mental disorders.. In BP all inflammatory markers were lowest in depressed state, with significant group differences after control for confounders with respect to TNF-R1 (p = 0.04), IL-1Ra (p = 0.02), OPG (p = 0.004) and IL-6 (p = 0.005). STNF-R1 was positively correlated with the item elevated mood (p = 0.02) whereas sad mood was negatively correlated with OPG (p = 0.0003), IL-1Ra (p = 0.001) and IL-6 (p = 0.006). Compared to controls the neutral mood group had significantly higher levels of OPG (p = 0.0003) and IL-6 (p = 0.005), and the elevated mood group had higher levels of TNF-R1 (p = 0.000005) and vWf (p = 0.002). There were no significant associations between affective states orsymptoms in SCZ.. The current associations between inflammatory markers and affective symptomatology in BP and not SCZ suggest that immune related mechanisms are associated with core psychopathology of BP.

Topics: Adult; Age Factors; Analysis of Variance; Biomarkers; Bipolar Disorder; Body Mass Index; C-Reactive Protein; Female; Humans; Immunoenzyme Techniques; Inflammation; Interleukin 1 Receptor Antagonist Protein; Interleukin-6; Male; Middle Aged; Osteoprotegerin; Psychiatric Status Rating Scales; Schizophrenia; Statistics as Topic; Tumor Necrosis Factor-alpha; von Willebrand Factor

Receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL) and osteoprotegerin (OPG) have been recently shown to play important roles in bone resorption. The aim of this study was to investigate the possible association between the expression of bone resorption regulators (RANKL and OPG) and inflammatory cell infiltration in chronic apical periodontitis.. The samples of chronic periapical lesions (n = 40) and healthy periapical tissues (n = 10) were examined for immunohistochemical analysis of RANKL and OPG. Lesion samples were further analyzed for the inflammatory infiltration condition. The inflammatory cell infiltration was scored in relation to immunohistochemical reactivity for CD3, CD20 and CD68.. The number of RANKL-positive cells and the ratio of RANKL/OPG in chronic apical periodontitis were significantly higher than those in healthy periapical tissues (P < 0.001). The number of RANKL-positive cells was higher in lesions with severe inflammatory infiltration than in those with light inflammatory infiltration (P < 0.05). Significantly increased RANKL expression was found with T lymphocytes (CD3(+)), macrophages (CD68(+)) and B lymphocytes (CD20(+)) infiltration (P < 0.05). No association was found between the ratio of RANKL/OPG and inflammatory cell infiltration.. RANKL expression was increased with T, B lymphocytes and macrophages infiltration, respectively in chronic periapical lesions. RANKL appears to be closely related to periapical inflammatory infiltrates. The relative ratio of RANKL/OPG may be a key determinant of RANKL-mediated bone resorption.

Topics: Adolescent; Adult; Chronic Periodontitis; Female; Humans; Immunohistochemistry; In Vitro Techniques; Inflammation; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Young Adult

Osteoprotegerin (OPG) is known to regulate bone mineral metabolism and to be also associated with inflammation, cardiovascular disease (CVD) and mortality. Malnutrition-inflammation-atherosclerosis (MIA) syndrome is commonly found and closely linked to mortality in dialysis patients. The aim of this study was to investigate the associations between OPG and MIA syndrome in prevalent peritoneal dialysis (PD) patients.. Prevalent PD patients for more than 6 months were prospectively followed up from March 2005 to May 2010. At baseline, OPG, hs-CRP, albumin, and %lean body mass (LBM) by creatinine kinetics were checked, and subjective global assessment (SGA) was performed. New-onset cardiovascular events were evaluated during the study period. Based on the median level of OPG, patients were classified as lower OPG (LO) group (n = 88) and higher OPG (HO) group (n = 88).. A total of 176 patients (age 52.0 ± 11.8 years, male 50.6%, duration of PD 105.3 ± 67.2 months) were recruited and followed. In HO group, age, hs-CRP level and Charlson's comorbidity indices were higher, whereas serum albumin level, %LBM and SGA score were significantly lower than LO group. OPG levels were positively correlated with inflammatory markers, whereas negatively correlated with nutritional status. Cardiovascular events occurred in 51 patients during the study period. Newly developed cardiovascular events were significantly common in HO group (n = 36, 40.9%) than LO group (n = 15, 17%, p = 0.002). Cox regression analysis revealed that higher OPG level (per 1-SD increase in OPG, HR: 1.44; 95% CI: 1.03-2.00; p = 0.034) was a significant risk factor for cardiovascular events even after adjustments for demographic and biochemical parameters.. OPG was significantly correlated with markers of systemic inflammation and malnutrition and was a significant predictor of CVD in PD patients. These findings suggest OPG might be a prognostic indicator of MIA syndrome in prevalent PD patients.

Topics: Adult; Biomarkers; Body Composition; C-Reactive Protein; Cardiovascular Diseases; Comorbidity; Creatinine; Female; Humans; Inflammation; Inflammation Mediators; Kaplan-Meier Estimate; Male; Malnutrition; Middle Aged; Osteoprotegerin; Peritoneal Dialysis; Prognosis; Proportional Hazards Models; Prospective Studies; Republic of Korea; Risk Assessment; Risk Factors; Serum Albumin; Time Factors; Up-Regulation

Bone mineral density decreases with antiretroviral therapy (ART) initiation, although the pathogenesis, including the role of tenofovir (TDF), is unclear. This study assessed changes in bone-turnover markers, osteoprotegerin (OPG), soluble receptor activator for nuclear factor-κβ ligand (sRANKL), and inflammation in subjects initiating TDF- versus non-TDF-containing regimens, and determined the relationship between bone turnover, OPG/sRANKL and inflammation.. This was a longitudinal observational study comparing levels of bone turnover markers (C-terminal telopeptide of type I collagen [CTX] and osteocalcin [OC]), OPG, sRANKL and inflammatory cytokines (soluble tumour necrosis factor [TNF]-α receptor [sTNFR]-I, sTNFR-II and interleukin-6) prior to ART and 6-12 months after ART initiation with a TDF- versus non-TDF-containing regimen in HIV-infected subjects 18-50 years old.. A total of 87 subjects were enrolled (TDF n=44 and non-TDF n=43). Groups were similar except subjects on TDF had a lower CD4(+) T-cell nadir (P<0.01) and were more likely to receive a protease inhibitor (PI; P=0.03). At pre-ART, 35% and 1% of subjects had CTX and OC above the normal range, respectively. Both increased with ART initiation, whereas OPG, sRANKL and inflammatory markers significantly decreased. In multivariate models, increases in OC were associated with TDF use, PI use and pre-ART levels of sTNFR-I, whereas increases in CTX were associated with CD4(+) T-cell nadir <50 cell/mm³. Increases in bone markers were unrelated to pre-ART levels of OPG/sRANKL and changes in OPG/sRANKL after ART initiation.. TDF use, PI use, TNF-α activity and advanced HIV disease are associated with changes in bone turnover markers, underscoring the complicated interaction between ART, bone turnover, inflammation and immune status, which extend beyond the OPG/RANKL system.

Topics: Adenine; Adolescent; Adult; Anti-HIV Agents; Biomarkers; Bone Density; Bone Remodeling; CD4 Lymphocyte Count; Collagen Type I; Cytokines; Female; HIV Infections; Humans; Inflammation; Longitudinal Studies; Male; NF-kappa B; Organophosphonates; Osteoprotegerin; Protease Inhibitors; RANK Ligand; Tenofovir; Tumor Necrosis Factor-alpha; Young Adult

Chronic obstructive pulmonary disease (COPD) is considered an inflammatory pulmonary disorder with systemic inflammatory manifestations. The aim of this study was to assess the systemic levels of six inflammatory mediators in a large cohort of COPD patients and controls. 409 COPD patients and 231 healthy subjects, aged 40-75 yrs, were included from the first phase of the Bergen COPD Cohort Study. All COPD patients were clinically diagnosed by a physician, and had a forced expiratory volume in 1 s/forced vital capacity ratio less than 0.7 and a smoking history of >10 pack-yrs. The plasma levels of C-reactive protein (CRP), soluble tumour necrosis factor receptor (sTNFR)-1, osteoprotegrin, neutrophil activating peptide-2, CXCL16 and monocyte chemoattractant protein-4 were determined by ELISA. After adjustment for all known confounders, COPD patients had significantly lower levels of osteoprotegrin than subjects without COPD (p<0.05), and higher levels of CRP (p<0.01). Among COPD patients, CRP was elevated in patients with frequent exacerbations (p<0.05). sTNFR-1 and osteoprotegrin were both related to Global Initiative for Chronic Obstructive Lung Disease stage and frequency of exacerbations in the last 12 months (p<0.05). In addition, sTNFR-1 was significantly associated with important comorbidities such as hypertension and depression (p<0.05). The present study confirms that certain circulating inflammatory mediators are an important phenotypic feature of COPD.

Topics: Adult; Aged; Biomarkers; C-Reactive Protein; Case-Control Studies; Chemokine CXCL16; Chemokines, CXC; Cohort Studies; Female; Humans; Inflammation; Male; Middle Aged; Monocyte Chemoattractant Proteins; Osteoprotegerin; Peptides; Pulmonary Disease, Chronic Obstructive; Receptors, Scavenger; Receptors, Tumor Necrosis Factor, Type I

Osteoporosis is characterized by low bone mass, microarchitectural deterioration of bone tissue leading to increased bone fragility, and a resulting susceptibility to fractures. Distinctive environmental bone marrow conditions appear to support the development and maintenance of the unbalance between bone resorption and bone formation; these complex bone marrow circumstances would be reflected in the fluid surrounding bone marrow cells. The content of regulatory molecules in the extracellular fluid from the human bone marrow is practically unknown. Since the content of cytokines such as adiponectin, leptin, osteoprogeterin (OPG), soluble receptor activator of nuclear factor kappaB ligand (s-RANKL), tumor necrosis factor alpha, and interleukin 6 (IL-6) may elicit conditions promoting or sustaining osteoporosis, in this work we compared the concentrations of the above-mentioned cytokines and also the level of the soluble receptors for both IL-6 and leptin in the extracellular fluid from the bone marrow of nonosteoporotic and osteoporotic human donors. A supernatant fluid (bone marrow supernatant fluid [BMSF]) was obtained after spinning the aspirated bone marrow samples; donors were classified as nonosteoporotic or osteoporotic after dual-energy X-ray absorptiometry (DXA) measuring. Specific commercially available kits were used for all measurements. The cytokines' concentration in BMSF showed differently among nonosteoporotic and osteoporotic women; this last group was characterized by higher content of proinflammatory and adipogenic cytokines. Also, osteoporotic BMSF differentiated by decreased leptin bioavailability, suggesting that insufficient leptin action may distinguish the osteoporotic bone marrow.

Topics: Absorptiometry, Photon; Adipocytes; Adipose Tissue; Aged; Biomarkers; Bone Marrow; Bone Resorption; Cytokines; Female; Humans; Inflammation; Osteoblasts; Osteoporosis, Postmenopausal; Osteoprotegerin; Postmenopause

Previous studies suggest a relationship between systemic inflammation and body composition in chronic obstructive pulmonary disease (COPD). We examined the relationships between body composition (fat free mass index (FFMI) kg·m(-2) and fat mass index (FMI) kg·m(-2)) and three plasma inflammatory markers C-reactive Protein (CRP), soluble tumour necrosis factor receptor 1 (sTNF-R1) and osteoprotegerin (OPG) in 409 stable COPD patients (aged 40-75 yrs, Global Initiative for Obstructive Chronic Lung Disease (GOLD) categories II-IV, 249 male) from the Bergen COPD Cohort Study in Norway. FFMI and FMI were measured by bioelectrical impedance. Plasma CRP (μg·mL(-1)), sTNF-R1 (pg·mL(-1)) and OPG (ng·mL(-1)) were determined by enzyme immunoassays. Correlations and Kruskal-Wallis tests were used for bivariate analyses. Linear regression models were fitted for each of the three markers, CRP, sTNF-R1 and OPG, with FFMI and FMI as explanatory variables including sex, age, smoking habits, GOLD category, hypoxaemia, Charlson Comorbidity Index and inhaled steroid use as potential confounders. CRP and sTNF-R1 levels correlated positively with both FFMI and FMI. The adjusted regression coefficients for an increase in logCRP per unit increase in FFMI was 1.23 (1.14-1.33) kg·m(-2) and 24.9 (11.8-38.1) kg·m(-2) for sTNF-R1. Higher FMI was associated with a lower OPG, with adjusted regression coefficient -0.14 (-0.23- -0.04), whereas FFMI was unrelated to OPG. In conclusion, COPD patients with low FFMI had lower not higher plasma levels of CRP and sTNF-R1, whereas higher fat mass was associated with higher CRP and sTNF-R1 and lower OPG.

Topics: Adult; Aged; Biomarkers; Body Composition; C-Reactive Protein; Cachexia; Cross-Sectional Studies; Female; Humans; Inflammation; Male; Middle Aged; Multivariate Analysis; Osteoprotegerin; Pulmonary Disease, Chronic Obstructive; Receptors, Tumor Necrosis Factor, Type I

Severe mental disorders are associated with elevated levels of inflammatory markers. In the present study, we investigated whether osteoprotegerin (OPG), a member of the tumour necrosis factor receptor family involved in calcification and inflammation, is elevated in patients with severe mental disorders.. We measured the plasma levels of OPG in patients with severe mental disorders (n = 312; 125 with bipolar disorder and 187 with schizophrenia) and healthy volunteers (n = 239).. The mean plasma levels of OPG were significantly higher in patients than in controls (t531 = 2.6, p = 0.01), with the same pattern in bipolar disorder and schizophrenia. The increase was significant after adjustment for possible confounding variables, including age, sex, ethnic background, alcohol consumption, liver and kidney function, diabetes, cardiovascular disease, autoimmune diseases and levels of cholesterol, glucose and C-reactive protein.. Owing to the cross-sectional design, it is difficult to determine causality.. Our results indicate that elevated OPG levels are associated with severe mental disorders and suggest that mechanisms related to calcification and inflammation may play a role in disease development.

Topics: Adult; Bipolar Disorder; Calcinosis; Cross-Sectional Studies; Female; Humans; Immunoenzyme Techniques; Inflammation; Male; Middle Aged; Osteoprotegerin; Risk Factors; Schizophrenia

The aim of the study was to evaluate the association between prevalence and severity of radiographic hand osteoarthritis (OA) and serum levels of systemic inflammatory markers in a community-based population sample.. A cross-sectional observational study was conducted on a population comprised 1452 Chuvashians (763 males, aged 49.23 ± 17.43; and 689 females, aged 50.37 ± 17.47 years). OA was evaluated in 14 joints of each hand using Kellgren and Lawrence (K-L), joint space narrowing (JSN) and osteophyte (OS) scores. Serum levels of systemic inflammatory and osteoclastogenic cytokines were measured by an enzyme-linked immunosorbent assay (ELISA). Statistical analyses included descriptive statistics, correlation analysis and multiple linear regressions.. Monocyte chemotactic protein-1 (MCP-1) and osteoprotegerin (OPG) levels were associated with OA traits, but the statistically significant correlations were weak and/or moderate. In particular, the MCP-1 inflammation marker showed a statistically significant association with JSN (β=0.077, P=0.022) and OS (β=0.067, P=0.024) scores, but not with the number of affected joints (K-L ≥ 2). OPG was significantly correlated with the scores as to the number of affected joints (β=0.063, P=0.035) and OS (β=0.077, P=0.028). No significant associations were found between levels of other inflammatory [interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-17] and osteoclastogenic [receptor activator for nuclear factor κ B ligand (RANKL), macrophage colony-stimulating factor (M-CSF)] cytokines and OA characteristics.. This study strengthens the premise that OPG might be a valid biomarker of hand OA. Confirmation of these results in larger cohorts of patients will reinforce our theory that the RANKL/OPG pathway is a suitable target for developing novel agents against OA.

Topics: Biomarkers; Chemokine CCL2; Cross-Sectional Studies; Cytokines; Female; Hand Joints; Humans; Inflammation; Interleukin-6; Linear Models; Macrophage Colony-Stimulating Factor; Male; Middle Aged; Osteoarthritis; Osteoprotegerin; Radiography; Receptor Activator of Nuclear Factor-kappa B; Tumor Necrosis Factor-alpha

The objective of the study was to investigate the role of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) in ankylosing spondylitis (AS). Serum levels of soluble RANKL (sRANKL) and OPG were measured in 42 AS patients and 26 healthy controls. We evaluated the AS patient's disease activity, functional ability, global assessment, and physical mobility and tested markers of systemic inflammation, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels. Serum levels of sRANKL [mean (SD), 4.75 (1.88) vs. 3.70 (1.14) pmol/l, p = 0.015] and OPG [mean (SD), 5.18 (1.19) vs. 4.52 (0.85) pmol/l, p = 0.026] were significantly higher in the 42 AS patients than the 26 healthy controls. Interestingly, serum OPG levels correlated significantly with ESR (r = 0.417, p = 0.007), CRP (r = 0.524, p < 0.001), tragus-to-wall distance (r = 0.556, p < 0.001), fingertip-to-floor distance (r = 0.423, p = 0.007), and occiput-to-wall distance (r = 0.465, p = 0.002) and correlated inversely with modified Schober index (r = -0.525, p = 0.001), cervical rotation (r = -0.403, p = 0.022), lateral lumbar flexion (r = -0.587, p < 0.001), and chest expansion (r = -0.553, p < 0.001). Moreover, in the AS patients with higher (> or =4.925 pmol/l, n = 21) serum OPG levels, there were significant increases in the tragus-to-wall distance (p = 0.007), fingertip-to-floor distance (p = 0.023), and CRP levels (p = 0.014) and decreased in the modified Schober index (p = 0.012), lateral lumbar flexion (p = 0.019), and chest expansion (p = 0.005). Serum levels of sRANKL and OPG are increased in the AS patients and may participate in the disease process of AS. Production of OPG has association with poor physical mobility and may reflect systemic inflammation in AS.

Topics: Adult; Blood Sedimentation; C-Reactive Protein; Female; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; Range of Motion, Articular; RANK Ligand; Seveso Accidental Release; Spondylitis, Ankylosing; Statistics, Nonparametric

Osteoprotegerin (OPG), receptor activator for nuclear factor kappa beta ligand (RANKL) and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) are newly discovered members of the tumour necrosis factor-alpha receptor superfamily. While their role in bone metabolism is well described, their function within the vasculature is poorly understood. OPG inhibits vascular calcification in vitro and high serum levels have been demonstrated in type 2 diabetes, but serum RANKL and TRAIL and their potential correlation with well-established biomarkers of subclinical vascular inflammation such as high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) have not been described.. Sixty-two patients with well-controlled type 2 diabetes and an age, gender and body mass index-matched group of 58 healthy individuals were recruited. Serum OPG, RANKL and TRAIL were measured using commercial enzyme-linked immunosorbent assays, as were hsCRP and IL-6.. Serum OPG, IL-6 and hsCRP levels, but not RANKL or TRAIL, were higher in patients with type 2 diabetes mellitus than in healthy controls, after adjustment for age and gender. After exclusion of diabetes patients with a history of micro- or macrovascular disease, OPG remained significantly higher in those with diabetes, but IL-6 and hsCRP levels were no longer elevated. There was a positive correlation between OPG and IL-6 in the group as a whole, but no correlation was found between RANKL or TRAIL and either hsCRP or IL-6.. OPG, but not RANKL or TRAIL, is significantly increased in type 2 diabetes. Higher OPG (but not IL-6 or hsCRP) in those without vascular disease suggests these biomarkers reflect separate pathophysiological processes in the vasculature.

Topics: Biomarkers; C-Reactive Protein; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Osteoprotegerin; RANK Ligand; TNF-Related Apoptosis-Inducing Ligand

Osteoprotegerin (OPG), an immunoregulatory member of the TNF receptor superfamily, is expressed in inflamed intestinal mucosa. We investigated whether OPG is produced by intestinal epithelial cells and tested the hypothesis that single-nucleotide polymorphisms (SNPs) in the gene encoding OPG (TNFRSF11B) are associated with traveler's diarrhea (TD) among North American travelers to Mexico.. OPG concentration was measured in the supernatants of T84 cells infected with various diarrheagenic Escherichia coli pathotypes. Genotyping was performed for 4 SNPs in the OPG gene for 968 North American travelers with or without TD. Stool samples from travelers with TD were evaluated for the presence of enteric pathogens.. T84 cells produced higher OPG levels in response to infection with various diarrheagenic E. coli pathotypes than with E. coli controls (P<.05). A SNP in the exon 1 region of the OPG gene (OPG+1181G>C) was associated with TD in white travelers who stayed in Mexico for >1 week during the summer (P=.009) and for TD due to nonsecretory pathogens (P=.001).. Our study suggests that OPG is secreted by intestinal epithelial cells in response to enteropathogens and that a polymorphism in the OPG gene is associated with an increased susceptibility to TD.

Topics: Adolescent; Adult; Analysis of Variance; Cell Line; Chi-Square Distribution; Diarrhea; Escherichia coli; Escherichia coli Infections; Feces; Female; Genetic Predisposition to Disease; Humans; Inflammation; Intestinal Mucosa; Male; Mexico; Middle Aged; Osteoprotegerin; Polymorphism, Single Nucleotide; Risk Factors; Travel

Periodontal ligament cells (PDLC) play a major role in periodontal tissues homeostasis and destruction. Most age-associated diseases seem to be closely related to an underlying chronic inflammatory state. Thus, the present study aimed at evaluating in PDLC the effect of aging on the basal levels of inflammatory and bone-related genes. Primary PDLC cultures were obtained from subjects aged 15-20 years (control- n=5), and subjects aged more than 60 years (test- n=5). Proliferation, cell viability and total secreted protein assays were performed, and mRNA levels were quantitatively assessed for interleukin (IL)-1beta, IL-4, IL-6 and IL-8, and for receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) by real time PCR. Data analysis demonstrated that aging negatively influenced cell proliferation, whereas cell viability and total secreted protein were not affected (p>0.05). Gene expression analysis showed that mRNA levels for RANKL and IL-8 were not affected by aging (p>0.05) whereas, mRNA levels for IL-4 was significantly lower in aged cells (p<0.05) and OPG, IL-1beta and IL-6 mRNA levels were higher (p<0.05). Data analysis suggests that aging decreased the ability of PDLC to proliferate and modulated the expression of important inflammatory and bone-related genes in periodontal ligament cells, favoring a proinflammatory and an antiresorptive profile.

Topics: Adolescent; Aged; Aging; Bone and Bones; Cell Proliferation; Cell Survival; Cells, Cultured; Female; Gene Expression Regulation; Humans; Inflammation; Interleukin-1beta; Interleukin-4; Interleukin-6; Interleukin-8; Male; Middle Aged; Osteoprotegerin; Periodontal Ligament; RANK Ligand; RNA, Messenger; Young Adult

Basic and clinical studies have suggested that inflammation predisposes to atrial fibrillation (AF). We assessed the association of 12 circulating inflammatory biomarkers (i.e., C-reactive protein, fibrinogen, interleukin-6, intercellular adhesion molecule-1, lipoprotein-associated phospholipase A2 [mass and activity], monocyte chemoattractant protein-1, myeloperoxidase, CD40 ligand, osteoprotegerin, P-selectin, and tumor necrosis factor receptor II) with incident AF in 2863 Framingham Offspring Study participants (mean age 60.7 years, SD = 9.4, 55% women). During follow-up (median 6 years), 148 participants (43% women) developed incident AF. In the multivariable proportional hazards models, the inflammatory biomarker panel was associated with incident AF (p = 0.03). With stepwise selection (p <0.01 for entry and retention), log-transformed osteoprotegerin was associated with incident AF (hazard ratio per SD 1.30, 95% confidence interval 1.08 to 1.56, p = 0.006). Adjusting for interim myocardial infarction or heart failure attenuated the association between osteoprotegerin and incident AF (hazard ratio 1.18, 95% confidence interval 0.98 to 1.43, p = 0.09). In conclusion, circulating osteoprotegerin concentration was significantly associated with incident AF in our community-based sample, possibly mediated by interim cardiovascular events.

Topics: Atrial Fibrillation; Biomarkers; C-Reactive Protein; Confidence Intervals; Female; Germany; Humans; Incidence; Inflammation; Male; Middle Aged; Multivariate Analysis; Odds Ratio; Osteoprotegerin; Prospective Studies; Risk Factors; Survival Analysis

Recent studies have suggested that vitamin D and an imbalance in calcium homeostasis may have an impact on the cardiovascular system. The aim of this study was to assess the impact of different concentrations of extracellular Ca(2+) on human umbilical vein cord endothelial cells (HUVEC) by measuring its effect on parameters involved in the pathogenesis of vascular inflammatory responses.. HUVEC were grown in the 3.5, 4.5 or 5.8 mg/dL concentration of extracellular Ca(2+) for 2-3 weeks. Expression of adhesion molecules was analysed by flow cytometry. Endothelial nitric oxide synthase (eNOS), receptor of advanced glycation end-product (RAGE) and interleukin-6 (IL-6) mRNA expressions were determined by real-time PCR. eNOS, inhibitor kappa Balpha (IkappaBalpha) and phosphorylated IkappaBalpha protein levels by Western blot, eNOS activity by conversion of [(14)C]-arginine to [(14)C]-citrulline, IL-6 and osteoprotegerin (OPG) secretion by ELISA and DNA-binding activity of nuclear factor kappa B (NFkappaB)-p65 were assayed colorimetrically in nuclear extracts.. In the presence of low Ca(2+) (3.5 mg/dL), protein expressions and activity of eNOS were diminished, while the protein expressions of intercellular adhesion molecule-1 (ICAM-1), as well as the mRNA expressions of RAGE and IL-6, were elevated. The protein secretions of IL-6 and OPG were also stimulated in low Ca(2+) concentration. At this concentration, the DNA-binding activity of NFkappaB was enhanced, probably due to the decreased level of IkappaBalpha.. These results suggest that lower extracellular ionized Ca(2+) may play a relevant role in modifying endothelial cells functions.

Topics: Calcium; Cells, Cultured; Endothelial Cells; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-6; NF-kappa B; Nitric Oxide Synthase Type III; Osteoprotegerin; Receptor for Advanced Glycation End Products; Receptors, Immunologic; RNA, Messenger

Rat adjuvant-induced arthritis (AIA) and collagen-induced arthritis (CIA) feature bone loss and systemic increases in TNFalpha, IL-1beta, and receptor activator of NF-kappaB ligand (RANKL). Anti-IL-1 or anti-TNFalpha therapies consistently reduce inflammation in these models, but systemic bone loss often persists. RANKL inhibition consistently prevents bone loss in both models without reducing joint inflammation. Effects of these therapies on systemic markers of bone turnover and inflammation have not been directly compared.. Lewis rats with established AIA or CIA were treated for 10 days (from day 4 post onset) with either PBS (Veh), TNFalpha inhibitor (pegsunercept), IL-1 inhibitor (anakinra), or RANKL inhibitor (osteoprotegerin (OPG)-Fc). Local inflammation was evaluated by monitoring hind paw swelling. Bone mineral density (BMD) of paws and lumbar vertebrae was assessed by dual X-ray absorptiometry. Markers and mediators of bone resorption (RANKL, tartrate-resistant acid phosphatase 5b (TRACP 5B)) and inflammation (prostaglandin E2 (PGE2), acute-phase protein alpha-1-acid glycoprotein (alpha1AGP), multiple cytokines) were measured in serum (day 14 post onset).. Arthritis progression significantly increased paw swelling and ankle and vertebral BMD loss. Anti-TNFalpha reduced paw swelling in both models, and reduced ankle BMD loss in AIA rats. Anti-IL-1 decreased paw swelling in CIA rats, and reduced ankle BMD loss in both models. Anti-TNFalpha and anti-IL-1 failed to prevent vertebral BMD loss in either model. OPG-Fc reduced BMD loss in ankles and vertebrae in both models, but had no effect on paw swelling. Serum RANKL was elevated in AIA-Veh and CIA-Veh rats. While antiTNFalpha and anti-IL-1 partially normalized serum RANKL without any changes in serum TRACP 5B, OPG-Fc treatment reduced serum TRACP 5B by over 90% in both CIA and AIA rats. CIA-Veh and AIA-Veh rats had increased serum alpha1AGP, IL-1beta, IL-8 and chemokine (C-C motif) ligand 2 (CCL2), and AIA-Veh rats also had significantly greater serum PGE2, TNFalpha and IL-17. Anti-TNFalpha reduced systemic alpha1AGP, CCL2 and PGE2 in AIA rats, while anti-IL-1 decreased systemic alpha1AGP, IL-8 and PGE2. In contrast, RANKL inhibition by OPG-Fc did not lessen systemic cytokine levels in either model.. Anti-TNFalpha or anti-IL-1 therapy inhibited parameters of local and systemic inflammation, and partially reduced local but not systemic bone loss in AIA and CIA rats. RANKL inhibition prevented local and systemic bone loss without significantly inhibiting local or systemic inflammatory parameters.

Topics: Animals; Antirheumatic Agents; Arthritis, Experimental; Arthritis, Rheumatoid; Bone Density; Enzyme-Linked Immunosorbent Assay; Immunohistochemistry; Inflammation; Interleukin 1 Receptor Antagonist Protein; Interleukin-1; Osteoprotegerin; RANK Ligand; Rats; Rats, Inbred Lew; Tumor Necrosis Factor-alpha

Osteoporosis results from an imbalance in skeletal remodeling that favors bone resorption over bone formation. Bone matrix is degraded by osteoclasts, which differentiate from myeloid precursors in response to the cytokine RANKL. To gain insight into the transcriptional regulation of bone resorption during growth and disease, we generated a conditional knockout of the transcription factor nuclear factor of activated T cells c1 (Nfatc1). Deletion of Nfatc1 in young mice resulted in osteopetrosis and inhibition of osteoclastogenesis in vivo and in vitro. Transcriptional profiling revealed NFATc1 as a master regulator of the osteoclast transcriptome, promoting the expression of numerous genes needed for bone resorption. In addition, NFATc1 directly repressed osteoclast progenitor expression of osteoprotegerin, a decoy receptor for RANKL previously thought to be an osteoblast-derived inhibitor of bone resorption. "Cherubism mice", which carry a gain-of-function mutation in SH3-domain binding protein 2 (Sh3bp2), develop osteoporosis and widespread inflammation dependent on the proinflammatory cytokine, TNF-alpha. Interestingly, deletion of Nfatc1 protected cherubism mice from systemic bone loss but did not inhibit inflammation. Taken together, our study demonstrates that NFATc1 is required for remodeling of the growing and adult skeleton and suggests that NFATc1 may be an effective therapeutic target for osteoporosis associated with inflammatory states.

Topics: Animals; Bone Diseases, Metabolic; Cherubism; Inflammation; Mice; Mice, Knockout; Mice, Transgenic; NFATC Transcription Factors; Osteoclasts; Osteoprotegerin

The aim of this study was to investigate sRANKL and OPG levels in serum and synovial fluid (SF) and to evaluate their relations in patients with RA in comparison to those with non-erosive arthritis (NEA). The study included 45 unselected RA patients with knee joint effusions and 27 patients with knee joint effusions because of NEA. Serum and SF samples were investigated isochronously. OPG and sRANKL were measured by ELISA assays. In RA, sRANKL levels were higher in serum than in SF (P = 0.007). In contrast, the NEA revealed higher sRANKL in SF compared to the serum (P = 0.001). Though in RA the average levels of sRANKL(ser) were 5.6 times and of sRANKL(syn) 1.5 times higher than in NEA, the differences were not significant. The free (unbound) OPG in SF was not significantly different in RA compared to NEA. Also in serum, the measured free OPG was only slightly higher in RA. There were no significant differences between RA and NEA concerning ESR and CRP. Significant correlations could be found between sRANKL(syn )and CRP (r = 0.453; P = 0.005) as well as ESR (r = 0.362; P = 0.033) in RA. Nearly a positive correlation was evident also between sRANKL(syn) and CRP in NEA (r = 0.520; P = 0.08). RA and NEA differ in particular concerning their power and intensity to destruct the juxtaarticular bone. This is the most remarkable finding of this study, that in RA a high part of sRANKL seems to be OPG bound and cleared by the blood stream, but the sRANKL neutralizing capacity of produced OPG in opposite to NEA is not sufficient to prevent osteoclast activation and bone destruction in the RA joint.

Topics: Adult; Arthritis, Rheumatoid; Biomarkers; Blood Sedimentation; C-Reactive Protein; Chronic Disease; Female; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Solubility; Synovial Fluid

Spondylarthritis (SpA) and rheumatoid arthritis (RA) have different patterns of bone damage, with more pronounced bone erosions in RA. The RANK/RANKL/osteoprotegerin (OPG) system plays a central role in bone resorption by promoting the maturation and activation of osteoclasts. To assess the potential role of this system in the distinct bone phenotype, we studied the synovial expression of these mediators in SpA and RA peripheral synovitis.. Synovial biopsy specimens were obtained from the actively inflamed peripheral joints of 35 patients with SpA and 19 patients with RA. Paired synovial biopsy samples were obtained from 24 patients with SpA after tumor necrosis factor alpha (TNFalpha) blockade. Synovial tissue sections were immunostained for RANKL, OPG, RANK, and TRAP and assessed by semiquantitative scoring and digital image analysis.. After extensive validation of the reactivity and specificity of the antibodies, we demonstrated the abundant expression of RANKL and OPG in SpA synovitis. RANKL was expressed by both fibroblast-like synoviocytes and sublining T lymphocytes. RANK-positive osteoclast precursors but no mature TRAP-positive osteoclasts were present in the inflamed tissue. The expression of these mediators was not different between patients with nonpsoriatic SpA, patients with psoriatic SpA, and patients with RA, was not related to the degree of systemic or local inflammation, and was not significantly modulated by highly effective treatment with TNFalpha blockers. Only the subset of patients with the best systemic response to TNFalpha blockade had decreased RANKL expression in the intimal lining layer.. The relative protection against bone erosions in SpA cannot be explained by qualitative or quantitative differences in the synovial expression of RANKL, OPG, and RANK. The abundant expression of these factors in SpA peripheral synovitis is largely disconnected from systemic and local inflammation.

Topics: Adult; Aged; Arthritis, Rheumatoid; Biopsy; Bone and Bones; Female; Humans; Inflammation; Male; Middle Aged; Osteoblasts; Osteoclasts; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Spondylarthritis; Synovial Membrane; Tumor Necrosis Factor-alpha

Several epidemiological studies have reported that temporomandibular disorder is more prevalent in women, which suggests the involvement of sex hormones, such as estrogen, in the pathogenesis of this disease. PCR amplification and Western blotting were employed to target the expression of estrogen receptors (ERs) in human fibroblast-like synovial and ATDC5 cells. The effect of estrogen was investigated through the expression of RANKL, osteoprotegerin (OPG), M-CSF/CSF-1 and c-fms. We showed expression of M-CSF/ CSF-1 and c-fms, with time-dependent increase in both after the addition of estrogen. Based on previous studies reporting that M-CSF/CSF-1 regulates the proliferation and differentiation of hemopoietic progenitor cells into mature macrophages, we put forward a new hypothesis based on the increased inflammation and tendency of females to suffer more from temporomandibular disorder (TMD) in the presence of external exacerbating factors. Detection of RANKL and OPG in ATDC5 and expression of both in HFLS was confirmed with complete disappearance of the RANKL band, and marked increase in the expression of OPG after 1 h from the addition of estrogen.

Topics: Aged; Animals; Blotting, Western; Bone Resorption; Cell Differentiation; Cell Line, Tumor; Cells, Cultured; Estrogens; Female; Fibroblasts; Gene Expression; Gonadal Steroid Hormones; Humans; Inflammation; Macrophage Colony-Stimulating Factor; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptor, Macrophage Colony-Stimulating Factor; Receptors, Estrogen; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Synovial Membrane; Temporomandibular Joint; Temporomandibular Joint Disorders

A middle-aged woman with recent-onset painful swollen fingers and widespread periostitis, elevated serum alkaline phosphatase (ALP) activity and erythrocyte sedimentation rate, and accelerated skeletal turnover was found not to have mutations in the gene sequences for exon 1 of receptor activator of nuclear factor-kappaB (RANK), osteoprotegerin (OPG), or sequestosome-1.. Hyperphosphatasia refers to disorders that feature elevated serum ALP activity (hyperphosphatasemia) usually from excesses of the bone isoform of ALP. Such conditions include familial expansile osteolysis, expansile skeletal hyperphosphatasia, and a familial form of early-onset Paget's disease of bone (PDB2), all from constitutive activation of RANK, and juvenile Paget's disease from OPG deficiency.. A 38-yr-old woman developed painful swollen fingers and achy bones after an episode of unexplained pericarditis and restrictive lung disease. Sequence analysis of exon 1 of TNFRSF11A encoding RANK, TNFRSF11B encoding OPG, and SQSTM1 encoding sequestosome-1 searched for mutations responsible for familial expansile osteolysis, expansile skeletal hyperphosphatasia, or PDB2, juvenile Paget's disease, or Paget's disease of bone (PDB), respectively.. Serum ALP and osteocalcin and urinary hydroxyproline were increased. Radiographs showed widespread, symmetric hyperostosis in the limbs where bone scintigraphy demonstrated enhanced radionuclide uptake. Iliac crest histology revealed accelerated skeletal turnover. No mutations were detected in the three genes examined. Three years of therapy with 70 mg alendronate orally once weekly improved symptoms, radiographic abnormalities, and biochemical markers.. Our patient manifested a unique, sporadic hyperphosphatasia syndrome. Unexplained, transient inflammation seemed to cause her pericarditis, restrictive lung disease, and periostitis with accelerated skeletal turnover that responded well to antiinflammatory drugs and alendronate therapy.

Topics: Adaptor Proteins, Signal Transducing; Adult; Alkaline Phosphatase; Biomarkers; Bone and Bones; Bone Density Conservation Agents; Female; Fingers; Humans; Inflammation; Osteoprotegerin; Pain; Periostitis; Radiography; Radionuclide Imaging; Receptor Activator of Nuclear Factor-kappa B; Sequestosome-1 Protein; Syndrome

Functional links between bone remodeling and the immune system in chronic inflammatory arthritis are mediated, in part, by the ligand of receptor activator of nuclear factor-kappa-B (RANK-L). Because neutrophils play a crucial role in chronic inflammation, the goal of this study was to determine whether proteins of the RANK/RANK-L pathway are expressed by synovial fluid (SF) neutrophils from patients with rheumatoid arthritis (RA) and to characterize this pathway in normal human blood neutrophils. The expression of RANK-L, osteoprotegerin (OPG), RANK, and tumor necrosis factor receptor-associated factor 6 (TRAF6) was determined by polymerase chain reaction, enzyme-linked immunosorbent assay, Western blotting, and cytofluorometry. RANK signaling was analyzed by the degradation of inhibitor of kappaB-alpha (I-kappaB-alpha). SF neutrophils from patients with RA express and release OPG and express the membrane-associated forms of RANK-L and RANK. In contrast, normal blood neutrophils express only the membrane-associated form of RANK-L. They do not express the mRNAs encoding OPG and RANK. SF neutrophils from RA patients and normal blood neutrophils release no soluble RANK-L. They express the mRNA for TRAF6. The expression of OPG and RANK by normal human blood neutrophils, however, can be induced by interleukin-4 + tumor necrosis factor-alpha and by SFs from patients with RA. In contrast, SFs from patients with osteoarthritis do not induce the expression of OPG and RANK. Moreover, the addition of RANK-L to normal blood neutrophils pretreated by SF from patients with RA decreased I-kappaB-alpha, indicating that RANK signaling by neutrophils stimulated with SF is associated with nuclear factor-kappa-B activation. In summary, RANK-L is expressed by inflammatory and normal neutrophils, unlike OPG and RANK, which are expressed only by neutrophils exposed to an inflammatory environment. Taken together, these results suggest that neutrophils may contribute to bone remodeling at inflammatory sites where they are present in significantly large numbers.

Topics: Arthritis, Rheumatoid; Blotting, Western; Bone Remodeling; Enzyme-Linked Immunosorbent Assay; Female; Humans; I-kappa B Proteins; Inflammation; Male; Middle Aged; Neutrophils; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Synovial Fluid; TNF Receptor-Associated Factor 6

Systemic inflammation is associated with ischemia and Alzheimer disease (AD). We hypothesized that inflammatory biomarkers would be associated with neuroimaging markers of ischemia (i.e., white matter hyperintensities [WMH]) and AD (i.e., total brain volume [TCB]).. MRI WMH and TCB were quantified on 1,926 Framingham Offspring participants free from clinical stroke, TIA, or dementia (mean age 60 +/- 9 years; range 35 to 85 years; 54% women) who underwent measurement of a circulating inflammatory marker panel, including CD40 ligand, C-reactive protein, interleukin-6 (IL-6), soluble intracellular adhesion molecule-1, monocyte chemoattractant protein-1, myeloperoxidase, osteoprotegerin (OPG), P-selectin, tumor necrosis factor-alpha (TNFalpha), and tumor necrosis factor receptor II. To account for head size, both TCB (TCBV) and WMH (WMH/TCV) were divided by total cranial volume. We used multivariable linear regression to relate 10 log-transformed inflammatory biomarkers to brain MRI measures.. In multivariable models, inflammatory markers as a group were associated with TCBV (p < 0.0001) but not WMH/TCV (p = 0.28). In stepwise models adjusted for clinical covariates with backwards elimination of markers, IL-6 and OPG were inversely associated with TCBV; TNFalpha was inversely related to TCBV in a subset of 1,430 participants. Findings were similar in analyses excluding individuals with prevalent cardiovascular disease. The relations between TCBV and inflammatory markers were modified by both sex and age, and generally were more pronounced in men and in older individuals.. Although our observational cross-sectional data cannot establish causality, they are consistent with the hypothesis that higher inflammatory markers are associated with greater atrophy than expected for age.

Topics: Adult; Age Distribution; Age Factors; Aged; Aged, 80 and over; Alzheimer Disease; Biomarkers; Brain; Brain Ischemia; Cardiovascular Diseases; Cross-Sectional Studies; Female; Humans; Inflammation; Inflammation Mediators; Interleukin-6; Magnetic Resonance Imaging; Male; Middle Aged; Osteoprotegerin; Sex Distribution; Tumor Necrosis Factor-alpha

We sought to determine whether fibrochondrocytes from menisci express receptor activator of NF-kappaB (RANK), its ligand (RANKL), or osteoprotegerin (OPG) and, if so, whether their expression is modulated by dynamic mechanical loading under inflammatory and normal conditions.. Fibrochondrocytes from rat menisci were subjected to cyclic tensile strain (CTS) at various magnitudes and frequencies in the presence or absence of interleukin (IL)-1beta for up to 24 h. In order to determine whether a possible regulatory effect of mechanical loading on RANKL and its receptors under inflamed conditions is sustained, cells were stimulated with IL-1beta for 24 h while being subjected to CTS only for the initial 4 and 8h, respectively. Regulation of RANKL, RANK, and OPG expression and synthesis were determined by semiquantitative and real-time PCR, Western blotting, and immunofluorescence.. Fibrochondrocytes constitutively expressed low levels of RANKL and RANK but marked levels of OPG. IL-1beta upregulated expression and synthesis of RANKL and RANK significantly (p<0.05), whereas expression of OPG was unaffected following 4 and 24 h. When fibrochondrocytes were simultaneously subjected to CTS and IL-1beta, expression of RANKL and RANK was significantly (p<0.05) downregulated as compared to that of IL-1beta-stimulated unstretched cells. The inhibitory effect of CTS on the IL-1beta-induced upregulation of RANKL and RANK was sustained as well as magnitude and frequency dependent.. Our study provides evidence that RANKL and its receptors are expressed in fibrochondrocytes from meniscus. These data also demonstrate that dynamic mechanical loading can modify the expression of RANKL and RANK in inflammatory conditions.

Topics: Animals; Cells, Cultured; Chondrocytes; Inflammation; Interleukin-1beta; Menisci, Tibial; Osteoprotegerin; RANK Ligand; Rats; Rats, Sprague-Dawley; Receptor Activator of Nuclear Factor-kappa B; RNA, Messenger; Stress, Mechanical

To assess the effect of osteoprotegerin (OPG) on joint swelling, synovial inflammation and cartilage destruction, periarticular and axial bone volume, and bone turnover in rat antigen-induced arthritis (AIA).. Rats were treated with OPG (3 mg/kg/day) at regular intervals from day 1 to day 20 of AIA. Disease activity was evaluated by measurement of joint swelling as well as, joint inflammation and destruction by histology. Bone volume and cellular turnover parameters of secondary spongiosa of the right tibia head and the third lumbar vertebra were evaluated by histomorphometry. Periarticular bone volume of the primary spongiosa at the right tibia head was measured by linear scanning. The findings were compared with those of PBS-treated AIA and healthy animals.. OPG treatment did not reduce joint swelling or histological signs of inflammation. Cartilage destruction was reduced. However, this effect did not reach statistical significance . In the secondary spongiosa OPG treatment reduced the loss of periarticular bone volume. However, the latter did not reach the level of healthy controls. OPG treatment significantly reduced parameters of bone formation and bone resorption. In the primary spongiosa, OPG-treatment led to a higher amount of mineralized tissue and a greater number of trabeculae compared to PBS-treated animals with AIA or healthy controls. In the axial skeleton, OPG treatment reduced bone formation and bone resorption parameters compared to healthy animals. This treatment had no influence on bone volume.. In periarticular bone of AIA rats, OPG treatment reduced the loss of bone volume and decreased the bone turnover, thus preventing periarticular bone destruction. OPG treatment had no influence on inflammatory process or on cartilage destruction.

Topics: Animals; Antigens; Arthritis, Experimental; Bone and Bones; Bone Diseases; Disease Models, Animal; Female; Inflammation; Knee Joint; Osteoprotegerin; Rats; Rats, Inbred Lew; Time Factors

To evaluate serum osteoprotegerin (OPG) concentrations in relation to age-dependent changes in serum markers of bone metabolism and systemic inflammation.. Two-hundred and eighty-three healthy subjects were evaluated for plasma estimated creatinine clearance (Cr-clearance), C-reactive protein (CRP), bone alkaline phosphatase, C-telopeptides of type-1 collagen (CrossLaps), nuclear factor-kappaB ligand (RANKL) and OPG concentrations.. In adult subjects (82 cases aged between 27 and 64 years) serum OPG concentrations were significantly and independently correlated with RANKL and Cr-clearance (R(2): 0.29), but not with CRP and biochemical markers of bone metabolism. In old subjects who were between 65 and 84 years of age (52 cases) serum OPG concentrations were significantly higher as compared with the adult subjects and correlated independently and significantly with serum RANKL, Cr-clearance and CrossLaps values (R(2): 0.63). The highest OPG values were found in the long-lived subjects (149 cases with ages between 85 and 110 years) who also showed increased serum CrossLaps and CRP concentrations as compared with the younger subjects. However, in the long-lived subjects serum OPG concentrations were significantly and independently correlated with Cr-clearance and CRP (R(2): 0.45) but not with CrossLaps values.. These data would suggest that different factors might be responsible for the age-dependent enhancement of OPG production. Bone metabolism would seem to be the most important factor influencing serum OPG concentrations in old subjects under 85 years of age, whereas in long-lived subjects the circulating values of this cytokine seem to be mainly correlated with serum CRP which could be a marker of inflammation and cardiovascular risk.

Topics: Adult; Aged; Aged, 80 and over; Aging; Biomarkers; Bone and Bones; Bone Remodeling; Carrier Proteins; Cytokines; Energy Metabolism; Female; Glycoproteins; Humans; Inflammation; Male; Membrane Glycoproteins; Middle Aged; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Bone disorders with increased osteoclastic bone resorption are frequently associated with bone pain and inhibitors of osteoclasts reduce bone pain. Osteoclasts degrade bone minerals by secreting protons through the vacuolar H+-ATPase, creating acidic microenvironments. Because acidosis is a well-known cause of pain, we reasoned that osteoclasts cause pain through proton secretion. We explored this using an animal model in which a single subcutaneous injection of the complete Freund's adjuvant (CFA) in the hind-paw caused inflammatory hyperalgesia (hyper-responsiveness to noxious stimuli). Osteoclastic bone resorption was increased in the metatarsal bones in the CFA-injected hind-paws. CFA-induced hyperalgesia was significantly suppressed by the bisphosphonates, zoledronic acid (ZOL) and alendronate and osteoprotegerin. c-src-deficient mice in which osteoclasts are inherently dysfunctional exhibited reduced CFA-induced hyperalgesia. Repeated subcutaneous injections of parathyroid hormone-related protein into the hind-paw also induced hyperalgesia with increased osteoclastic bone resorption. The hyperalgesia was associated with increased mRNA expression of acid-sensing ion channel (ASIC) 1a, 1b and 3 in the ipsi-lateral dorsal root ganglions (DRGs) by RT-PCR and c-Fos in the ipsi-lateral spinal dorsal horn by immunohistochemistry. Of note, ZOL decreased the ASIC1a mRNA expression and c-Fos. Treatment of the DRG cell line F-11 with acid (pH5.5) increased ASIC1a, 1b and 3 mRNA expression and nuclear c-Fos expression. The ASIC blocker amiloride inhibited acid-induced c-Fos expression in F-11 cells. Moreover, F-11 cells transfected with the transient receptor potential channel vanilloid subfamily member 1 (TRPV1) showed increased acid-induced nuclear c-Fos expression compared with parental F-11 cells. Finally, bafilomycin A1, an inhibitor of the vacuolar H+-ATPase, reversed the hyperalgesia and down-regulated ASIC1a mRNA expression in the DRGs. These results led us to propose that osteoclasts play a part in CFA-induced inflammatory pain through an activation of the acid-sensing receptors including ASICs and TRPV1 by creating acidosis.

Topics: Acid Sensing Ion Channels; Animals; Bone and Bones; Bone Resorption; Cell Line; Diphosphonates; Freund's Adjuvant; Genes, src; Hyperalgesia; Inflammation; Injections, Intravenous; Injections, Spinal; Injections, Subcutaneous; Macrolides; Male; Membrane Proteins; Mice; Mice, Mutant Strains; Nerve Tissue Proteins; Osteoclasts; Osteoprotegerin; Pain; Parathyroid Hormone; Posterior Horn Cells; Reverse Transcriptase Polymerase Chain Reaction; Sodium Channels; TRPV Cation Channels; Vacuolar Proton-Translocating ATPases

Coronary artery calcification may play a significant role in the pathophysiology of plaque progression and healing. We hypothesized that osteoprotegerin, an inhibitor of osteoclastogenesis, may participate in the calcification of coronary plaques or the response to injury after coronary stenting. A prospective registry was performed in 2004. Blood samples from 100 patients undergoing percutaneous coronary intervention (PCI) were obtained before PCI and 24 h after PCI. The concentrations of osteoprotegerin (OPG), C-reactive protein, interleukin-6, and soluble CD40 ligand (sCD40L) were determined by ELISA. Quantitative coronary angiography was performed to define the presence of culprit lesion calcification (CLC). Comparisons among markers of inflammation and tertiles of OPG were stratified with respect to CLC. Patients with CLC (n = 28) compared with no CLC (n = 71) were older (P < 0.01), had lower creatinine clearance (P < 0.01), lower hemoglobin (P = 0.02), and were less likely to smoke (P = 0.04). Patients without CLC were over twice as likely to present with a marker-positive acute coronary syndrome. CLC was associated with less pre-PCI platelet-mediated inflammation as measured by sCD40L (4.65 vs. 7.15 pg/ml, P = 0.05), but not with lower levels of OPG. Inflammatory cytokines increased significantly after PCI for patients with and without CLC. For patients in the highest tertile of OPG at baseline, there was a reduction in OPG after PCI. Systemic osteoprotegerin levels are not associated with angiographic calcification of culprit plaques. For patients with elevated levels of OPG prior to PCI, there is a significant reduction after PCI consistent with a counterregulatory role for OPG.. Both calcified and non-calcified culprit plaques exhibited a similar inflammatory response to stent-mediated injury. After PCI, osteoprotegerin decreased while proinflammatory cytokines increased, which may be consistent with a counterregulatory role for osteoprotegerin.

Topics: Aged; Angioplasty, Balloon, Coronary; Calcinosis; Cardiomyopathies; Coronary Angiography; Coronary Vessels; Cytokines; Female; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; Prospective Studies; Stents

Inflammatory bone diseases are characterized by the presence of pro-inflammatory cytokines that regulate bone turnover. Osteoprotegerin (OPG) is a soluble osteoblast-derived protein that influences bone resorption by inhibiting osteoclast differentiation and activation. In the present study, we demonstrate that interleukin-1beta and tumor necrosis factor alpha induce OPG mRNA production and OPG secretion by osteoblast-like MG-63 cells. Maximum induction of OPG secretion by either cytokine requires activation of the p38 mitogen activated protein kinase (MAPK) pathway but neither the p42/p44 (ERK) nor the c-Jun N-terminal MAPK pathways. Induction of OPG mRNA by either cytokine is also p38 MAPK dependent. Taken together, these data indicate that cytokine-induced OPG gene expression and protein secretion are differentially regulated by specific MAP kinase signal transduction pathways.

Topics: Blotting, Western; Cell Line; Cell Line, Tumor; Cytokines; DNA, Complementary; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Glycoproteins; Humans; Inflammation; Interleukin-1; JNK Mitogen-Activated Protein Kinases; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Osteoblasts; Osteoclasts; Osteoprotegerin; p38 Mitogen-Activated Protein Kinases; Protein Structure, Tertiary; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Messenger; Signal Transduction; Time Factors; Tumor Necrosis Factor-alpha

Nucleotides, released from cells during inflammation and by mechanical stimulation, act through the P2 family of nucleotide receptors. Previous studies have demonstrated the expression of P2Y1 and P2Y2 receptors in osteoclasts. The aim of this study was to determine whether osteoclast P2Y receptors signal through NF-kappaB, a key transcription factor regulating osteoclastogenesis. Immunofluorescence was used to detect the p65 subunit of NF-kappaB, which upon activation translocates from the cytosol to nuclei. Low levels of NF-kappaB activation were observed in untreated rabbit osteoclasts and in those exposed to 2-methylthio ADP (P2Y1 agonist) or ATP or UTP (P2Y2 agonists). In contrast, UDP or INS48823 (P2Y6 agonists) induced a significant increase in the number of cells exhibiting NF-kappaB activation, a process sensitive to the proteasome inhibitor lactacystin. In osteoclasts purified by micromanipulation, reverse transcription-PCR revealed the presence of P2Y1, P2Y2, and P2Y6 receptor transcripts, and application of agonists for these receptors induced the transient rise of cytosolic calcium. Treatment of rat osteoclasts with UDP or INS48823, but not 2-methylthio ADP or UTP, increased osteoclast survival. Osteoprotegerin (a decoy receptor for RANK ligand) did not significantly alter the effects of UDP on NF-kappaB localization or osteoclast survival, consistent with a direct action. Moreover, SN50 (cell-permeable peptide inhibitor of NF-kappaB) suppressed the enhancement of cell survival induced by UDP and INS48823. Our findings demonstrate the presence of functional P2Y6 receptors in osteoclasts. Thus, nucleotides, following their release at sites of inflammation and mechanical stimulation, can act through P2Y6 receptors to initiate NF-kappaB signaling and enhance osteoclast survival.

Topics: Active Transport, Cell Nucleus; Adenosine Diphosphate; Adenosine Triphosphate; Alkaline Phosphatase; Animals; Bone and Bones; Calcium; Cell Nucleus; Cell Survival; Cells, Cultured; Cytosol; DNA Primers; Dose-Response Relationship, Drug; Enzyme Inhibitors; Glycoproteins; Inflammation; Ligands; Microscopy, Fluorescence; NF-kappa B; Osteoclasts; Osteoprotegerin; Proteasome Inhibitors; Purinergic P2 Receptor Agonists; Rabbits; Rats; Rats, Wistar; Receptors, Cytoplasmic and Nuclear; Receptors, Purinergic P2; Receptors, Purinergic P2Y1; Receptors, Purinergic P2Y2; Receptors, Tumor Necrosis Factor; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Time Factors; Transcription Factor RelA; Uridine Diphosphate; Uridine Triphosphate

Calcific aortic valve sclerosis involves inflammatory processes and occurs preferentially on the aortic side of endothelialized valve leaflets. Although the endothelium is recognized to play critical roles in focal vascular sclerosis, the contributions of valvular endothelial phenotypes to aortic valve sclerosis and side-specific susceptibility to calcification are poorly understood. Using RNA amplification and cDNA microarrays, we identified 584 genes as differentially expressed in situ by the endothelium on the aortic side versus ventricular side of normal adult pig aortic valves. These differential transcriptional profiles, representative of the steady state in vivo, identify globally distinct endothelial phenotypes on opposite sides of the aortic valve. Several over-represented biological classifications with putative relevance to endothelial regulation of valvular homeostasis and aortic-side vulnerability to calcification were identified among the differentially expressed genes. Of note, multiple inhibitors of cardiovascular calcification were significantly less expressed by endothelium on the disease-prone aortic side of the valve, suggesting side-specific permissiveness to calcification. However, coexisting putative protective mechanisms were also expressed. Specifically, enhanced antioxidative gene expression and the lack of differential expression of proinflammatory molecules on the aortic side may protect against inflammation and lesion initiation in the normal valve. These data implicate the endothelium in regulating valvular calcification and suggest that spatial heterogeneity of valvular endothelial phenotypes may contribute to the focal susceptibility for lesion development.

Topics: Animals; Antioxidants; Aortic Valve; Bone Morphogenetic Protein 4; Bone Morphogenetic Proteins; Calcinosis; Endothelial Cells; Gene Expression Profiling; Glycoproteins; Heart Valve Diseases; Hemodynamics; Inflammation; Male; NF-kappa B; Osteoprotegerin; Phenotype; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Swine

RANKL is an essential mediator of bone erosions, but the role of RANKL in systemic bone loss had not been studied in arthritis. RANKL protein was increased in rat joint extracts and serum at the earliest stages of arthritis. Osteoprotegerin (OPG) treatment reversed local and systemic bone loss, suggesting that RANKL is both a marker and mediator of bone loss in arthritis.. RANKL is well established as an essential mediator of bone erosions in inflammatory arthritis, but the role of RANKL in systemic bone loss in arthritis had not been studied. We hypothesized that serum RANKL could serve as both a mediator and as a novel biomarker for local and systemic bone loss in arthritis. We challenged this hypothesis in two established rat models of inflammatory arthritis. We sought to determine whether serum RANKL was elevated early in disease progression and whether RANKL suppression could prevent both local and systemic bone loss in these models.. Detailed time-course studies were conducted in animals with collagen-induced (CIA) or adjuvant-induced (AIA) arthritis to evaluate the onset and progression of inflammation (paw swelling), bone erosions, osteoclast numbers, and RANKL protein levels in arthritic joints and in serum. Additional CIA and AIA rats (n=8/group) received placebo (PBS) or recombinant OPG (3 mg/kg three times weekly) for 10 days beginning 4 days after disease onset (first macroscopic evidence of hind paw erythema and edema) to assess the role of RANKL in local and systemic bone loss.. RANKL protein was significantly elevated in the joints and serum of CIA and AIA rats within 1-2 days of disease onset. Increased RANKL levels were associated with local (hind paw) and systemic (vertebral) osteopenia in both models. The RANKL inhibitor OPG prevented local and systemic osteopenia in both models of established disease.. RANKL protein is significantly increased both locally and systemically during the earliest stages of inflammatory arthritis in rats, suggesting that serum RANKL might have prognostic value for bone erosions and systemic osteopenia in this condition. RANKL inhibition through OPG prevented local and systemic bone loss in these arthritis models, suggesting that RANKL inhibition is a promising new approach for treating bone loss in arthritis.

Topics: Animals; Arthritis, Experimental; Biomarkers; Bone Diseases, Metabolic; Carrier Proteins; Disease Models, Animal; Female; Glycoproteins; Inflammation; Joints; Male; Membrane Glycoproteins; Osteoprotegerin; RANK Ligand; Rats; Rats, Inbred Lew; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Heme oxygenase 1 (HO-1) plays an important role in vascular disease, transplantation, and inflammation. In animal models of acute and chronic inflammation, induction of HO-1 has anti-inflammatory and cytoprotective properties. Since inflammation is an important trigger of osteoclastogenesis, we hypothesized that HO-1 might influence osteoclastogenesis. We investigated the effects of induction of HO-1 on osteoclast formation in vitro and in vivo. Furthermore, we addressed the role of HO-1 in inflammatory bone loss in humans. When HO-1 was induced by hemin in vitro, a significant dose-dependent inhibition of osteoclastogenesis was observed. Up-regulation of HO-1 was mediated by activation of MAPK and primarily prevented differentiation of osteoclast precursors to osteoclasts, whereas it did not affect mature osteoclasts. Anti-osteoclastogenic properties of hemin were based on a down-regulation of c-fms, RANK, TRAF-6, and c-fos. In addition, induction of HO-1 inhibited TNF-triggered osteoclast differentiation in vitro as well as LPS-driven inflammatory bone loss in vivo. Furthermore, HO-1 induction suppressed osteoclastogenesis and bone destruction in a TNF-mediated arthritis. In line, assessment of synovial tissue from rheumatoid arthritis patients revealed that osteoclasts are usually HO-1 negative. Moreover, serum levels of bilirubin, a metabolite of HO-1, were elevated in rheumatoid arthritis patients without bone damage, suggesting HO-1 affects bone loss in humans. In summary, these data indicate that HO-1 negatively regulates osteoclastogenesis, leading to a positive net balance of bone.

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Bilirubin; Bone and Bones; Bone Resorption; Cell Nucleus; Dose-Response Relationship, Drug; Down-Regulation; Enzyme Activation; Glycoproteins; Heme Oxygenase-1; Hemin; Humans; In Vitro Techniques; Inflammation; Lipopolysaccharides; Mice; Models, Biological; Osteoclasts; Osteoprotegerin; Proto-Oncogene Proteins c-fos; Receptor, Macrophage Colony-Stimulating Factor; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Spleen; TNF Receptor-Associated Factor 6; Up-Regulation

We examined the association between serum osteoprotegerin (OPG) levels, systemic inflammation and arterial stiffness in normal and diabetic patients.. The study subjects comprised 49 newly diagnosed diabetic patients and 72 age- and sex-matched normal glucose controls. Anthropometric parameters, blood pressure, fasting blood glucose (FBG), lipid profiles, serum OPG, high-sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6) and brachial-ankle pulse wave velocity (baPWV) were measured.. Serum OPG levels (6.1 +/- 1.4 vs. 5.4 +/- 1.3 pmol/l, P = 0.011) and baPWV (1562 +/- 354 vs. 1399 +/- 257 cm/s, P = 0.004) were significantly higher in the diabetic group than in the normal glucose group. Serum OPG levels in normal and diabetic patients correlated significantly with systolic blood pressure (r = 0.20, P = 0.035), FBG (r = 0.30, P = 0.002), right baPWV (r = 0.22, P = 0.021), left baPWV (r = 0.26, P = 0.006), homeostasis model assessment insulin resistance (HOMA-IR) (r = 0.19, P = 0.045), IL-6 (r = 0.32, P = 0.001) and hsCRP (r = 0.21, P = 0.027) after adjusting for age and sex. Multiple regression analysis showed that serum OPG level was significantly associated with age, FBG, IL-6, systolic blood pressure, triglyceride and hsCRP (R(2) = 0.299).. In summary, serum OPG and baPWV levels are elevated in diabetic patients and serum OPG levels are significantly associated with inflammation and arterial stiffness.

Topics: Biomarkers; Blood Glucose; Brachial Artery; C-Reactive Protein; Case-Control Studies; Diabetes Mellitus; Female; Glycoproteins; Humans; Hypertension; Inflammation; Insulin Resistance; Interleukin-6; Lipids; Male; Middle Aged; Osteoprotegerin; Pulsatile Flow; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Regression Analysis; Signal Processing, Computer-Assisted; Systole; Triglycerides

To determine the contribution of IL-1beta, tumor necrosis factor alpha (TNF-alpha) and IL-17 to AP-1, NF-kappaB and Egr-1 activation in rheumatoid arthritis, the effect of the cytokines used alone or in combination was measured on TF expression in rheumatoid synoviocytes. Effects on mRNA expression were measured by RT-PCR and effects on nuclear translocation were measured by immunocytochemistry. To assess the functional consequences of cytokine induction, osteoprotegerin levels were measured in synoviocyte supernatants.IL-1beta and TNF-alpha alone at optimal concentration (100 pg/ml) induced the nuclear translocation of NF-kappaB and almost all AP-1 members, except JunB and Egr-1 for IL-1beta and except Fra-2 and Egr-1 for TNF-alpha. IL-17 was clearly less potent since no nuclear translocation was observed, except for a weak activation of Fra-1 and NF-kappaB. More importantly, when these cytokines were used at low concentrations, their combination showed a synergistic effect on almost all the TFs, except for Egr-1, with a particular effect on Fra-1 and NF-kappaB. Increased recruitment of additional factors was induced when the three cytokines were combined. IL-1 and TNF-alpha induced mRNA expression of c-jun while IL-17 had no effect. A synergistic effect was seen with their combination. A similar synergistic effect was observed for osteoprotegerin production when these three cytokines were combined at low concentrations.AP-1 and NF-kappaB pathways were highly sensitive to the combination through synergistic mechanisms. These effects observed in rheumatoid arthritis synoviocytes may reflect the conditions found in the rheumatoid arthritis joint and may contribute to the mode of action of cytokine inhibitors.

Topics: Active Transport, Cell Nucleus; Arthritis, Rheumatoid; Cells, Cultured; DNA-Binding Proteins; Early Growth Response Protein 1; Glycoproteins; Humans; Immediate-Early Proteins; Inflammation; Interleukin-1; Interleukin-17; NF-kappa B; Osteoprotegerin; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; RNA, Messenger; Synovial Membrane; Transcription Factor AP-1; Transcription Factors; Tumor Necrosis Factor-alpha

Osteoprotegerin Ligand (OPGL) is a member of the tumor necrosis factor ligand superfamily and has been shown to be involved in interactions between T cells and dendritic cells. Its role in monocyte effector function, however, has not been defined. In the present study a role for OPGL in activating monocytes/macrophages has been characterized. OPGL was found to up-regulate receptor activator of NF-kappaB (RANK) receptor expression on monocytes, regulate their effector function by inducing cytokine and chemokine secretion, activate antigen presentation through up-regulation of co-stimulatory molecule expression, and promote survival. This activation is mediated through the MAPK pathway as evidenced by activation of p38 and p42/44 MAPK and up-regulation of BCL-XL protein levels. A physiological role for OPGL in monocyte activation and effector function was tested in a model of lipopolysaccharide-induced endotoxic shock. Administration of receptor activator of NF-kappaB (RANK)-Fc to block OPGL activity in vivo was able to protect mice from death induced by sepsis, indicating a hitherto undescribed role for OPGL in monocyte function and in mediating inflammatory response. This was further tested in an animal model of inflammation-mediated arthritis. Treatment with RANK-Fc significantly ameliorated disease development and attenuated bone destruction. Thus, our study strongly suggests that administration of receptor fusion proteins to specifically block OPGL activity in vivo may result in blocking development of monocyte/macrophage-mediated diseases.

Topics: Animals; Apoptosis; Arthritis; bcl-X Protein; Blotting, Western; Carrier Proteins; Cell Division; Cell Separation; Cell Survival; Cells, Cultured; Chemokines; Cytokines; Dose-Response Relationship, Drug; Flow Cytometry; Glycoproteins; Humans; Immunoglobulin G; Inflammation; Ligands; Lipopolysaccharides; Macrophages; MAP Kinase Signaling System; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Monocytes; NF-kappa B; Osteoprotegerin; p38 Mitogen-Activated Protein Kinases; Proto-Oncogene Proteins c-bcl-2; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; Time Factors; Tomography, X-Ray Computed; Up-Regulation

To evaluate the respective action of IL-4, an anti-inflammatory cytokine, and OPG, an inhibitor of bone resorption, on the inflammatory process and the associated bone resorption in collagen-induced arthritis (CIA). After CIA induction, DBA/1 mice were treated with OPG or with IL-4 DBA/1 transfected fibroblasts or both OPG + IL-4. CIA significantly improved in IL-4 groups. OPG had no effect on arthritis clinical scores but histologic scores were reduced in OPG, IL-4, and OPG + IL-4 groups vs. nontreated CIA mice. OPG increased significantly BMD and decreased by 45% D-pyridinolin levels. Moreover association of IL-4 and OPG exerted an additive effect of BMD and resorption marker (-68%). Production of IFN-gamma in the supernatants of spleen cells was reduced in IL-4 treated mice. OPG had a moderate effect on IFN-gamma, but potentiated the inhibitory effect of IL-4. OPG and IL-4 prevent bone loss in CIA-mice model and could have additive effects on IFN-gamma secretion.

Topics: Animals; Arthritis; Bone Resorption; Cell Line; Collagen; Drug Therapy, Combination; Fibroblasts; Genetic Therapy; Glycoproteins; Inflammation; Interferon-gamma; Interleukin-4; Male; Mice; Mice, Inbred DBA; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Transfection

Rheumatoid arthritis (RA) is associated with focal and systemic bone loss involving cytokines such as RANKL and TNF-alpha. RANK-L promotes focal and systemic osteoporosis, whereas osteoprotegerin (OPG) inhibits bone resorption. Although anti-TNF-alpha antibodies (anti-TNF-alpha Ab) decrease joint inflammation and bone erosions, their effects on bone loss are unknown. The aim of this study was to evaluate the effects of OPG and anti-TNF-alpha Ab, separately or in combination, on inflammation and bone remodeling in collagen-induced arthritis (CIA), a model of RA.. DBA/1 mice (n=28) were immunized with bovine type II collagen and treated with OPG-Fc or anti-TNF-alpha Ab or both, or saline. One group of mice (n=7) was not immunized (naive group). Urinary deoxypyridinoline (D-pyr) and whole-body bone mineral density (BMD) were measured at baseline and at sacrifice. Histomorphometric parameters were evaluated at the femoral metaphysis.. Anti-TNF-alpha Ab, but not OPG, decreased the clinical arthritis score (P<0.02 vs. saline) and the histological score of inflammation. The BMD change from baseline to sacrifice (DeltaBMD) was significantly smaller in CIA mice than naive mice. OPG and anti-TNF-alpha Ab significantly increased DeltaBMD versus saline, and the effect was greater with OPG (P<0.003). DeltaD-pyr decreased by 65% with OPG and 13% with anti-TNF-alpha Ab. Compared with saline, OPG increased trabecular bone volume (BV/TV) (P<0.02), decreased trabecular separation (P<0.02), and decreased the bone formation rate (BFR) (P<0.01). Anti-TNF-alpha Ab produced no significant changes in bone volume or trabecular separation but increased trabecular thickness (P<0.02 vs. saline) to a value close to that in naive mice, suggesting preservation of bone formation. No additive effects of OPG and anti-TNF-alpha Ab were found.. Systemic OPG and anti-TNF-alpha Ab therapy prevented bone loss in CIA mice through distinct mechanisms involving decreased bone resorption and preserved bone formation. Combining these two agents might help to prevent bone loss in inflammatory diseases.

Topics: Amino Acids; Animals; Antibodies; Arthritis, Experimental; Bone Density; Bone Resorption; Femur; Glycoproteins; Inflammation; Male; Mice; Mice, Inbred DBA; Osteogenesis; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha

Autoimmune associated bone disease and intestinal inflammation are closely linked with deregulation and hyperactivation of autoreactive CD4 T cells. How these T cells are activated and mediate disease is not clear. Here we show that in the Interleukin 2-deficient mouse model of autoimmunity spontaneous osteopenia and colitis are caused by increased production of the ligand for receptor activator of NFkappaB (RANKL). RANKL acting via its receptor, receptor activator of NFkappaB (RANK), increases bone turnover and promotes intestinal dendritic cell (DC) survival in vivo. Modulation of RANKL-RANK interactions with exogenous recombinant osteoprotegerin (Fc-OPG) reverses skeletal abnormalities and reduces colitis by decreasing colonic DC numbers. This study identifies a common causal link between bone disease and intestinal inflammation and establishes the importance of DC in mediating colonic inflammation in vivo.

Topics: Adjuvants, Immunologic; Animals; Bone and Bones; Bone Diseases, Metabolic; Carrier Proteins; Colon; Dendritic Cells; Glycoproteins; Homeodomain Proteins; Inflammation; Interleukin-2; Membrane Glycoproteins; Mice; Mice, Transgenic; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; T-Lymphocytes

Osteoprotegerin (OPG), a natural negative regulator of osteoclastogenesis and bone resorption, may be a potential therapeutic agent for treatment of osteolysis-associated prosthetic joint loosening. Using an in vivo adeno-associated virus (AAV)-mediated gene transfer technique, this study was designed to evaluate the protective effects of OPG transgene against orthopedic wear debris-induced bone loss in a murine model of osteolysis.. Bone tissue was implanted into established pouches on BALB/c mice, followed by the introduction of ultra-high-molecular-weight polyethylene (UHMWPE) particles to provoke inflammation and osteolysis. The viruses encoding human OPG gene (rAAV-hOPG) or beta-galactosidase marker gene (rAAV-LacZ) were injected into the air pouches, and the tissue was harvested 7 days after viral infection for histologic and molecular analyses.. Successful transgene expression was confirmed by the detection of OPG by enzyme-linked immunosorbent assay and positive X-Gal staining of pouch tissue (LacZ). Real-time polymerase chain reaction indicated significant diminishment of messenger RNA expression of osteoclast markers in OPG-transduced pouches compared with rAAV-LacZ-transduced pouches. The transduction and expression of OPG also markedly decreased the gene copies of the biologic receptor activator of nuclear factor kappaB. The expression of OPG in the bone-implanted pouch reduced bone calcium release by a mean of 39% compared with the calcium release in the other 2 groups. Computerized image analysis revealed that expression of OPG significantly protected against bone collagen loss.. OPG gene transfer mediated by rAAV effectively protects against particulate polyethylene-induced bone resorption in this experimental model. Data suggest that gene transfer using rAAV-OPG may be a feasible and effective therapeutic candidate to treat or prevent wear debris-associated osteolysis and aseptic loosening.

Topics: Animals; Cell Division; Dependovirus; Gene Expression; Gene Transfer Techniques; Genetic Vectors; Glycoproteins; Humans; Inflammation; Mice; Mice, Inbred BALB C; Osteoclasts; Osteolysis; Osteoprotegerin; Polyethylene; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Transduction, Genetic

Fracture healing is a unique biological process regulated by a complex array of signaling molecules and proinflammatory cytokines. Recent evidence for the role of tumor necrosis family members in the coupling of cellular functions during skeletal homeostasis suggests that they also may be involved in the regulation of skeletal repair. The expression of a number of cytokines and receptors that are of functional importance to bone remodeling (osteoprotegerin [OPG], macrophage colony-stimulating factor [M-CSF], and osteoprotegerin ligand [receptor activator of NF-kappaB ligand (RANKL)]), as well as inflammation (tumor necrosis factor alpha [TNF-alpha] and its receptors, and interleukin-1alpha [IL-1alpha] and -beta and their receptors) were analyzed over a 28-day period after the generation of simple transverse fractures in mouse tibias. OPG was expressed constitutively in unfractured bones and elevated levels of expression were detected throughout the repair process. It showed two distinct peaks of expression: the first occurring within 24 h after fracture and the second at the time of peak cartilage formation on day 7. In contrast, the expression of RANKL was nearly undetectable in unfractured bones but strongly induced throughout the period of fracture healing. The peak in expression of RANKL did not correlate with that of OPG, because maximal levels of expression were seen on day 3 and day 14, when OPG levels were decreasing. M-CSF expression followed the temporal profile of RANKL but was expressed at relatively high basal levels in unfractured bones. TNF-alpha, lymphotoxin-beta (LT-beta), IL-1alpha, and IL-1beta showed peaks in expression within the first 24 h after fracture, depressed levels during the period of cartilage formation, and increased levels of expression on day 21 and day 28 when bone remodeling was initiated. Both TNF-alpha receptors (p55 and p75) and the IL-1RII receptor showed identical patterns of expression to their ligands, while the IL-1R1 was expressed only during the initial period of inflammation on day 1 and day 3 postfracture. Both TNF-alpha and IL-1alpha expression were localized primarily in macrophages and inflammatory cells during the early periods of inflammation and seen in mesenchymal and osteoblastic cells later during healing. TNF-alpha expression also was detected at very high levels in hypertrophic chondrocytes. These data imply that the expression profiles for OPG, RANKL, and M-CSF are tightly coupled during fracture

Topics: Animals; Bony Callus; Carrier Proteins; Cartilage; Cytokines; Fracture Healing; Glycoproteins; Inflammation; Interleukin-1; Macrophage Colony-Stimulating Factor; Male; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Interleukin-1; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha