osteoprotegerin and Calcinosis

This meta-analysis included published data on the relationship between levels of osteoprotegerin, an important molecule in the bone production process, and the risk of accumulation of calcium deposits in the vessels supplying blood to the heart. Since these calcium deposits are an early sign of heart disease and subsequently heart attacks, understanding the mechanisms and finding ways to treat patients earlier can be of great importance. This study found that the higher the osteoprotegerin level a patient has, the higher the patient's chance of having calcium deposits in his or her heart vessels.

Topics: Biomarkers; Calcinosis; Coronary Artery Disease; Coronary Vessels; Humans; Osteoprotegerin; Prognosis; Prospective Studies; Risk Factors

Osteoprotegerin (OPG) is a key regulator in bone metabolism, that also has effect in vascular system. Studies suggest that osteoprotegerin is a critical arterial calcification inhibitor, and is released by endothelial cells as a protective mechanism for their survival in certain pathological conditions, such as diabetes mellitus, chronic kidney disease, and other metabolic disorders. That has been shown in studies in vitro and in animal models. The discovery that OPG deficient mice (OPG -/- mice) develop severe osteoporosis and arterial calcification, has led to conclusion that osteoprotegerin might be mulecule linking vascular and bone system. Paradoxically however, clinical trials have shown recently that OPG serum levels is increased in coronary artery disease and correlates with its severity, ischemic cardial decompensation, and future cardiovascular events. Therefore it is possible that osteoprotegerin could have a new function as a potential biomarker in early identification and monitoring patients with cardiovascular disease. Amongst that osteoprotegerin is in association with well known atherosclerosis risc factors: undoubtedly it is proven its relationship with age, smoking and diabetes mellitus. There is evidence regarding presence of hyperlipoproteinemia and increased serum levels of osteoprotegerin. Also the researches have been directed in genetic level, linking certain single nucleotid genetic polymorphisms of osteoprotegerin and vascular calcification appearance. This review emphasises multifactorial role of OPG, presenting numerous clinical and experimental studies regarding its role in vascular pathology, suggesting a novel biomarker in cardiovascular diseases, showing latest conclusions about this interesting topic that needs to be further explored.

Topics: Animals; Blood Vessels; Calcinosis; Humans; Osteoprotegerin; Prognosis

Vascular calcification is highly associated with cardiovascular disease mortality, particularly in high-risk patients with diabetes and chronic kidney diseases (CKD). In blood vessels, intimal calcification is associated with atherosclerosis, whereas medial calcification is a nonocclusive process which leads to increased vascular stiffness and reduced vascular compliance. In the valves, calcification of the leaflets can change the mechanical properties of the tissue and result in stenosis. For many decades, vascular calcification has been noted as a consequence of aging. Studies now confirm that vascular calcification is an actively regulated process and shares many features with bone development and metabolism. This review provides an update on the mechanisms of vascular calcification including the emerging roles of the RANK/RANKL/OPG triad, osteoclasts, and microRNAs. Potential treatments adapted from osteoporosis and CKD treatments that are under investigation for preventing and/or regressing vascular calcification are also reviewed.

Topics: Animals; Antibodies, Monoclonal, Humanized; Atherosclerosis; Calcinosis; Calcium; Chelating Agents; Denosumab; Diphosphonates; Humans; Mice; MicroRNAs; Osteoclasts; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Renal Insufficiency, Chronic; Teriparatide; Tunica Intima; Tunica Media; Vascular Calcification; Vascular Diseases

Vitamin K is required for the activity of various biologically active proteins in our body. Apart from clotting factors, vitamin K-dependent proteins include regulatory proteins like protein C, protein S, protein Z, osteocalcin, growth arrest-specific gene 6 protein, and matrix Gla protein. Glutamic acid residues in matrix Gla protein are γ-carboxylated by vitamin K-dependent γ-carboxylase, which enables it to inhibit calcification. Warfarin, being a vitamin K antagonist, inhibits this process, and has been associated with calcification in various animal and human studies. Though no specific guidelines are currently available to prevent or treat this less-recognized side effect, discontinuing warfarin and using an alternative anticoagulant seems to be a reasonable option. Newer anticoagulants such as dabigatran and rivaroxaban offer promise as future therapeutic options in such cases. Drugs including statins, alendronate, osteoprotegerin, and vitamin K are currently under study as therapies to prevent or treat warfarin-associated calcification. Copyright © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.

Topics: Anticoagulants; Calcinosis; Diphosphonates; Heart Valve Diseases; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperbaric Oxygenation; Muscle, Smooth, Vascular; Osteoprotegerin; Vitamin K; Warfarin

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

Coronary artery disease (CAD) represents the most relevant cause of death and morbidity in the adult population of developed and developing countries. During the last decades, a strong research effort has been performed to identify more selective markers and better assess the cardiovascular risk in both primary and secondary prevention.. This review updates current knowledge regarding the pathophysiological relevance as possible markers of coronary calcification of the receptor activator of nuclear factor-kappa ligand (RANKL)/osteoprotegerin (OPG) system. Furthermore, the potential clinical use of both RANKL/OPG and coronary calcium score (CAC) to assess cardiovascular vulnerability has been discussed.. Emerging evidence indicates that atherosclerotic plaque calcification is positively correlated with vulnerability. Several inflammatory mediators have been shown to modulate arterial calcification, thus increasing the risk of plaque rupture. Among these factors, RANKL/OPG axis might be of particular interest as a promising biomarker of plaque vulnerability in subjects with diffuse coronary calcification.. Together with clinical parameters of coronary calcification (such as CAC), circulating RANKL/OPG levels could contribute to better assess and predict cardiac events.

Topics: Biomarkers; Calcinosis; Cardiovascular Diseases; Coronary Artery Disease; Humans; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Risk Factors

Analysis of animal models is indispensable to elucidate the molecular mechanism in vascular calcification (VC) as well as to develop new therapies for VC. Various gene-modified mice that show VC have been reported, and considerable progress has been made through the analyses of these animals. Mice of which bone-calcification regulatory factors were modified are the representative animal models for VC, indicating that these factors certainly regulate VC as well as bone-calcification. Inducible VC in wild-type animals is also an important research tool for developing preventive and therapeutic approach for VC.

Topics: Animals; Animals, Genetically Modified; Bone Morphogenetic Protein 2; Calcinosis; Calcium-Binding Proteins; Disease Models, Animal; Extracellular Matrix Proteins; Matrix Gla Protein; Membrane Proteins; Mice; Osteoprotegerin; Phosphate Transport Proteins; Phosphoric Diester Hydrolases; Pyrophosphatases; Vascular Diseases

Vascular calcification often associates with bone-cartilage formation. Artery sclerotic lesions accompany the expression of bone matrix proteins such as osteopontin, osteocalcin and matrix Gla protein and transcription factors including Runx2, osterix and Sox9. These lesions also express BMP, osteoprotegerin (OPG) and RANKL, which are important factor regulating bone formation and resorption. MGP-deficient mice exhibited extensive artery calcification as well as OPG-deficient mice. Thus, bone metabolism-related factors actively participate in vascular calcification, which had been interpreted as a passive calcification due to dystrophic calcification.

Topics: Animals; Bone Morphogenetic Proteins; Calcinosis; Calcium-Binding Proteins; Cell Differentiation; Chondrocytes; Core Binding Factor Alpha 1 Subunit; Extracellular Matrix Proteins; Humans; Matrix Gla Protein; Mice; Osteoblasts; Osteocalcin; Osteogenesis; Osteopontin; Osteoprotegerin; RANK Ligand; Transcription Factors; Vascular Diseases

Recently, the multidetector computed tomography (CT) is available to measure quantitative analysis of coronary vascular calcification (coronary calcification score [CACscore]). Vascular calcification is recognized not only in the end stage of atherosclerosis but also in the early stage of atherosclerosis. Recent data suggested that bone- related factors are closely related to coronary artery disease and vascular calcification. In this review, we discuss for regulatory mechanisms of vascular calcification.

Topics: Alkaline Phosphatase; alpha-2-HS-Glycoprotein; Biomarkers; Blood Proteins; Calcinosis; Calcium-Binding Proteins; Coronary Artery Disease; Extracellular Matrix Proteins; Humans; Matrix Gla Protein; Osteopontin; Osteoprotegerin; Parathyroid Hormone; Phosphates; Tomography, Spiral Computed

The association of bone pathologies with atherosclerosis has stimulated the search for common mediators linking the skeletal and the vascular system. Since its initial discovery as a key regulator in bone metabolism, osteoprotegerin (OPG) has become the subject of intense interest for its role in vascular disease and calcification. Studies in vitro and in animal models suggest that OPG inhibits vascular calcification. Paradoxically however, clinical studies suggest that serum OPG levels increase in association with vascular calcification, coronary artery disease, stroke and future cardiovascular events. This has led to an extensive debate on the potential of OPG as a biomarker of vascular disease. However the exact significance and mechanisms by which this bone-regulatory protein influences cardiovascular pathophysiology is still unclear. The need for a more complete picture is being addressed in increasing valuable research indicating OPG as not only a marker but also a mediator of vascular pathology modulating osteogenic, inflammatory and apoptotic responses. By integrating the results of recent experimental research, animal models and clinical studies, this review summarises the present understanding of the role of OPG in vascular disease and calcification.

Topics: Animals; Atherosclerosis; Calcinosis; Disease Models, Animal; Humans; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand

Cardiovascular disease is the leading cause of mortality in patients with end-stage renal disease (ESRD) and is attributed to a combination of traditional and non-traditional cardiovascular risk factors. In recent years, there has also been an increasing recognition of a very high prevalence of cardiovascular calcification in the ESRD population, including in patients receiving long-term peritoneal dialysis (PD). Numerous observational cohort studies have demonstrated the prognostic importance of cardiovascular calcifications in these patients. The mechanisms are not completely understood, but are likely multifactorial. The present article reviews the prevalence, clinical course, prognostic significance, and some contributing factors for vascular and valvular calcification in ESRD patients, including patients receiving PD therapy.

Topics: 1-Carboxyglutamic Acid; alpha-2-HS-Glycoprotein; Blood Proteins; Blood Vessels; C-Reactive Protein; Calcinosis; Calcium-Binding Proteins; Extracellular Matrix Proteins; Heart Valve Diseases; Heart Valves; Humans; Kidney Failure, Chronic; Matrix Gla Protein; Osteoprotegerin; Peritoneal Dialysis; Prevalence; Prognosis; Vascular Diseases

Osteoporosis and atherosclerosis are degenerative disorders of old age that often present together, but recently it has been suggested that the association between osteoporosis and cardio-vascular diseases is not just due to the aging process. The osteoprotegerin (OPG)/receptor activator of nuclear factor-kB (RANK)/RANK ligand (RANKL) system has been identified as a possible mediator of arterial calcification suggesting common links between osteoporosis and vascular diseases. Since the discovery of the OPG/RANK/RANKL system, much has been learned about its role in controlling skeletal biology; however, its role in the context of vascular biology is only beginning to be explored. It has been suggested that OPG might act as an autocrine/paracrine regulator of vascular calcification and might be useful as a serum marker of vascular disease. However, the exact role of OPG (or RANKL/RANK) in vascular calcification is still not completely understood. This review aims to report the recent findings on the relationship between osteoporosis and OPG/RANK/RANKL-mediated vascular disease.

Topics: Animals; Bone and Bones; Calcinosis; Humans; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction; Vascular Diseases

Experimental and clinical trials in the field of bone biology helped to clarify the role of receptors, which belong to the tumor necrosis factor family, such as osteoprotegerin and receptor activator of nuclear factor kappaB (RANK), in the regulation of bone remodeling. The ligand of the receptor activator of nuclear factor kappaB (RANKL) is a stimulator of bone resorption, while osteoprotegerin is the soluble "decoy" receptor to RANKL, protecting thereby bone from resorption. Pathological states of bone remodeling (like osteoporosis) are associated with imbalance in the activity of osteoprotegerin and the receptor activator of nuclear factor kappaB. Recent studies, however, also indicate that the osteoprotegerin/RANKL/RANK system has important roles in the regulation of the immune and vascular system as well. In this review we summarize the function and regulation of osteoprotegerin, its role in pathological states--primarily in cardiovascular diseases--and its relevance as a marker of cardiovascular risk. Finally, we present our prospective trial performed among the chronic dialyzed patients, where we examined the association between the cardiovascular mortality, osteoprotegerin levels and the arterial stiffness.

Topics: Aged; Analysis of Variance; Animals; Biomarkers; Blood Flow Velocity; Bone Diseases; Bone Remodeling; Calcinosis; Cardiovascular Diseases; Carotid Arteries; Female; Femoral Artery; Heart Rate; Humans; Kaplan-Meier Estimate; Kidney Failure, Chronic; Linear Models; Male; Middle Aged; Osteoprotegerin; Prospective Studies; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Renal Dialysis; Risk Assessment; Risk Factors; Time Factors; Vascular Diseases; Vascular Resistance; Vasodilation

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

In the last decade, the nephrology community has focused its attention on the main cause of morbidity and mortality in chronic renal failure patients: cardiovascular disease. In addition, recent studies pointed out that vascular calcification (VC) is a major cause of cardiovascular disease in the dialysis population. Interestingly, the pathogenesis of VC and soft tissue calcification in chronic kidney disease (CKD) has been extensively investigated. Nowadays we know that VC is associated not only with passive calcium phosphate deposition, but also with an active, cell-mediated process. To better understand the pathogenesis of VC in CKD, numerous regulatory proteins have been studied, because of their ability to inhibit mineral deposition in the vessels. We here examine the state of the art of those substances recognized as regulatory key factors in preventing VC in uremic conditions, such as fetuin A (alpha2-Heremans-Schmid glycoprotein), matrix gamma-carboxyglutamic acid protein, pyrophosphate, osteoprotegerin and bone morphogenetic protein. We conclude that at present it is too early to introduce these novel markers into clinical practice.

Topics: 1-Carboxyglutamic Acid; alpha-Fetoproteins; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Calcinosis; Diphosphates; Humans; Kidney Failure, Chronic; Models, Biological; Osteoprotegerin; Risk Factors; Transforming Growth Factor beta; Uremia; Vascular Diseases

Vascular calcification, a degenerative process considered in the past to be a passive procedure, has now been suggested to be related to ossification. Many proteins responsible for bone formation have been identified on the arterial wall. The OPG/RANKL/RANK axis, responsible for ossification and bone mineralization, seems to play a major role in vasculature and atherosclerosis. Mice lacking OPG gene present osteoporosis and arterial calcification, while overexpression of OPG gene leads to osteopetrosis. In the present review the latest knowledge related to the effects of the OPG/RANKL/RANK axis on vasculature, including atherosclerosis, will be analyzed. The clinical significance of circulating OPG and RANKL levels in vascular diseases will also be referred.

Topics: Animals; Calcinosis; Mice; Models, Biological; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Vascular Diseases

Atherosclerosis and vascular calcification often co-exist in chronic kidney disease (CKD) patients. Although the former has been recently recognized as an active inflammatory process, atherosclerosis-related calcification of the intima is still viewed as a passive epiphenomenon. Recent experimental data showed that ossification of the internal vascular wall might also be an active inflammatory process interrelated to atherosclerosis. Factors like RANKL (receptor activator of nuclear factor kappaB ligand), RANK and osteoprotegerin modulate vascular calcification and at the same time are involved in the process of atherosclerosis. Moreover, basic calcium phosphate crystals could interact with and activate monocytes-macrophages that produce proinflammatory cytokines capable of initiating - via endothelial activation and leukocyte adhesion - the atherosclerotic process. Thus, vascular calcification might be an active player and not simply an epiphenomenon in atherosclerosis. Should the above-mentioned data be confirmed in future studies, calcification of the internal vascular wall and atherosclerosis might be viewed and treated as tightly interconnected and linked by inflammation processes in CKD patients.

Topics: alpha-2-HS-Glycoprotein; Atherosclerosis; Blood Proteins; Calcinosis; Calcium Phosphates; Humans; Kidney Failure, Chronic; Lipoproteins, LDL; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Vascular Diseases

Severity of coronary artery calcification is closely related to atherosclerotic plaque burden and cardiac event rate. Recent data have suggested that vascular calcification is an actively regulated process similar to the bone formation, and that bone-related factors may be involved in the development of vascular calcification. Non-invasive prediction of calcified coronary artery disease is important using serum bone-related markers. Among them, we focus on matrix Gla protein, osteoprotegerin and fetuin-A as such candidates in this review.

Topics: alpha-2-HS-Glycoprotein; Animals; Biomarkers; Blood Proteins; Calcinosis; Calcium-Binding Proteins; Coronary Artery Disease; Coronary Disease; Extracellular Matrix Proteins; Humans; Matrix Gla Protein; Myocardial Infarction; Osteoprotegerin; Predictive Value of Tests; Severity of Illness Index

Atherogenesis is characterized by an intense inflammatory process, involving immune and vascular cells. These cells play a crucial role in all phases of atherosclerotic plaque formation and complication through cytokine, protease, and prothrombotic factor secretion. The accumulation of inflammatory cells and thus high amounts of soluble mediators are responsible for the evolution of some plaques to instable phenotype which may lead to rupture. One condition strongly associated with plaque rupture is calcification, a physiopathological process orchestrated by several soluble factors, including the receptor activator of nuclear factor (NF)kappaB ligand (RANKL)/receptor activator of nuclear factor (NF)kappaB (RANK)/osteoprotegerin (OPG) system. Although some studies showed some interesting correlations with acute ischemic events, at present, more evidences are needed to evaluate the predictive and diagnostic value of serum sRANKL and OPG levels for clinical use. The major limitation is probably the poor specificity of these factors for cardiovascular disease. The identification of tissue-specific isoforms could increase the importance of sRANKL and OPG in predicting calcified plaque rupture and the dramatic ischemic consequences in the brain and the heart.

Topics: Animals; Atherosclerosis; Biomarkers; Calcinosis; Humans; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Vascular calcification significantly impairs cardiovascular physiology, and its mechanism is under investigation. Many of the same factors that modulate bone osteogenesis, including cytokines, hormones, and lipids, also modulate vascular calcification, acting through many of the same transcription factors. In some cases, such as for lipids and cytokines, the net effect on calcification is positive in the artery wall and negative in bone. The mechanism for this reciprocal relation is not established. A recent series of reports points to the possibility that two bone regulatory factors, receptor activator of NF-kappaB ligand (RANKL) and its soluble decoy receptor, osteoprotegerin (OPG), govern vascular calcification and may explain the phenomenon. Both RANKL and OPG are widely accepted as the final common pathway for most factors and processes affecting bone resorption. Binding of RANKL to its cognate receptor RANK induces NF-kappaB signaling, which stimulates osteoclastic differentiation in preosteoclasts and induces bone morphogenetic protein (BMP-2) expression in chondrocytes. A role for RANKL and its receptors in vascular calcification is spported by several findings: a vascular calcification phenotype in mice genetically deficient in OPG; an increase in expression of RANKL, and a decrease in expression of OPG, in calcified arteries; clinical associations between coronary disease and serum OPG and RANKL levels; and RANKL induction of calcification and osteoblastic differentiation in valvular myofibroblasts.

Topics: Animals; Atherosclerosis; Calcinosis; Humans; Osteogenesis; Osteoprotegerin; RANK Ligand; TNF-Related Apoptosis-Inducing Ligand; Vascular Diseases

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

Osteoprotegerin (OPG) is a bone-related protein that is also present in the vasculature. Recent data suggest that it may play a special role in arterial disease among patients with diabetes. Diabetic macroangiopathy is characterized by a series of diffuse, non-atherosclerotic alterations that hypothetically increase the vulnerability of the vessel wall to atherogenic processes. One prominent feature of the macroangiopathy is linear media calcifications, which have been found to impose a strong risk of future cardiovascular events in epidemiological studies. The mechanisms behind the development of calcifications are unknown, but may be related to the occurrence of diffuse matrix alterations in the arterial wall in diabetes. Interestingly, we have recently observed that the amounts of OPG are increased in the tunica media in arterial tissue from diabetic patients. OPG has been linked to vascular calcifications in immunohistochemical analysis of atherosclerotic tissue and experimental studies on OPG knockout mice. Thus, it is possible that increased arterial OPG concentrations reflect an osteogenic transformation of the vasculature in patients with diabetes as an aspect of diabetic macroangiopathy. This review will evaluate data about OPG in the vasculature and focus on a possible role of OPG in the arterial wall in diabetes.

Topics: Animals; Arteriosclerosis; Calcinosis; Diabetic Angiopathies; Endothelium, Vascular; Glycoproteins; Humans; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Vascular calcification, long thought to result from passive degeneration, involves a complex, regulated process of biomineralization resembling osteogenesis. Evidence indicates that proteins controlling bone mineralization are also involved in the regulation of vascular calcification. Artery wall cells grown in culture are induced to become osteogenic by inflammatory and atherogenic stimuli. Furthermore, osteoclast-like cells are found in calcified atherosclerotic plaques, and active resorption of ectopic vascular calcification has been demonstrated. In general, soft tissue calcification arises in areas of chronic inflammation, possibly functioning as a barrier limiting the spread of the inflammatory stimulus. Atherosclerotic calcification may be one example of this process, in which oxidized lipids are the inflammatory stimulus. Calcification is widely used as a clinical indicator of atherosclerosis. It progresses nonlinearly with time, following a sigmoid-shaped curve. The relationship between calcification and clinical events likely relates to mechanical instability introduced by calcified plaque at its interface with softer, noncalcified plaque. In general, as calcification proceeds, interface surface area increases initially, but eventually decreases as plaques coalesce. This phenomenon may account for reports of less calcification in unstable plaque. Vascular calcification is exacerbated in certain clinical entities, including diabetes, menopause, and osteoporosis. Mechanisms linking them must be considered in clinical decisions. For example, treatments for osteoporosis may have unanticipated effects on vascular calcification; the converse also applies. Further understanding of processes governing vascular calcification may yield new therapeutic options for vascular disease.

Topics: Animals; Arteriosclerosis; Calcinosis; Calcium-Binding Proteins; Diabetes Mellitus; Endpoint Determination; Extracellular Matrix Proteins; Glycoproteins; Humans; Matrix Gla Protein; Menopause; Mice; Mice, Knockout; Minerals; Osteogenesis; Osteopontin; Osteoporosis; Osteoprotegerin; Phosphates; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Sialoglycoproteins

Vascular calcification often occurs with advancing age, atherosclerosis, various metabolic disorders such as diabetes mellitus and end-stage renal disease, or in rare genetic diseases, leading to serious clinical consequences. Such mineralization can occur at various sites (cardiac valves, arterial intima or media, capillaries), involve localized or diffuse widespread calcification, and result from numerous causes that provoke active inflammatory and osteogenic processes or disordered mineral homeostasis. Although valuable research has defined many key factors and cell types involved, surprising new insights continue to arise that deepen our understanding and suggest novel research directions or strategies for clinical intervention in calcific vasculopathies. One emerging area in vascular biology involves the RANKL/RANK/OPG system, molecules of the tumor necrosis factor-related family recently discovered to be critical regulators of immune and skeletal biology. Evidence is accumulating that such signals may be expressed, regulated, and function in vascular physiology and pathology in unique ways to promote endothelial cell survival, angiogenesis, monocyte or endothelial cell recruitment, and smooth muscle cell osteogenesis and calcification. Concerted research efforts are greatly needed to understand these potential roles, clarify whether RANKL (receptor activator of nuclear factor kappaB ligand) promotes and osteoprotegerin (OPG) protects against vascular calcification, define how OPG genetic polymorphisms relate to cardiovascular disease, and learn whether elevated serum OPG levels reflect endothelial dysfunction in patients. Overall, the RANKL/RANK/OPG system may mediate important and complex links between the vascular, skeletal, and immune systems. Thus, these molecules may play a central role in regulating the development of vascular calcification coincident with declines in skeletal mineralization with age, osteoporosis, or disease.

Topics: Animals; Arteriosclerosis; Bone and Bones; Calcinosis; Carrier Proteins; Endothelium, Vascular; Glycoproteins; Humans; Immune System; Membrane Glycoproteins; Mice; Mice, Knockout; Muscle, Smooth, Vascular; Osteoclasts; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

In 1997, investigators isolated a secreted glycoprotein that blocked osteoclast differentiation from precursor cells, prevented osteoporosis (decreased bone mass) when administered to ovariectomized rats, and resulted in osteopetrosis (increased bone mass) when overexpressed in transgenic mice. Since then, the isolation and characterization of the protein named osteoprotegerin (OPG) has stimulated much work in the fields of endocrinology, rheumatology, and immunology. OPG functions as a soluble decoy receptor for receptor activator of nuclear factor-kappaB ligand (RANKL, or OPG ligand) and shares homologies with other members of the tumor necrosis factor receptor superfamily. OPG acts by competing with the receptor activator of nuclear factor-kappaB, which is expressed on osteoclasts and dendritic cells for specifically binding to RANKL. RANKL is crucially involved in osteoclast functions and bone remodeling as well as immune cell cross-talks, dendritic cell survival, and lymph node organogenesis. More recently, emerging evidence from in vitro studies and mouse genetics attributed OPG an important role in vascular biology. In fact, OPG could represent the long sought-after molecular link between arterial calcification and bone resorption, which underlies the clinical coincidence of vascular disease and osteoporosis, which are most prevalent in postmenopausal women and elderly people.

Topics: Animals; Arteries; Bone and Bones; Bone Remodeling; Bone Resorption; Calcinosis; Carrier Proteins; Glycoproteins; Humans; Membrane Glycoproteins; Mice; Osteopetrosis; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

Topics: Animals; Arteries; Arteriosclerosis; Calcinosis; Calcium-Binding Proteins; Extracellular Matrix; Extracellular Matrix Proteins; Glycoproteins; Humans; Matrix Gla Protein; Minerals; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

The biomarker Osteoprotegerin (OPG) is associated with coronary artery disease (CAD). The main purpose of this study was to evaluate the diagnostic value of OPG in healthy subjects and in patients with suspected angina pectoris (AP).. A total of 1805 persons were enrolled: 1152 healthy subjects and 493 patients with suspected AP. For comparison 160 patients with acute myocardial infarction (MI) were included. To uncover subclinical coronary atherosclerosis, a non-contrast cardiac-CT scan was performed in healthy subjects; while in patients with suspected AP a contrast coronary angiography was used to detect significant stenosis. OPG concentrations were analyzed and compared between groups. ROC-analyses were performed to estimate OPG cut-off values.. OPG concentrations increased according to disease severity with the highest levels found in patients with acute MI. No significant difference (p = 0.97) in OPG concentrations was observed between subgroups of healthy subjects according to severity of coronary calcifications. A significant difference (p < 0.0001) in OPG concentrations was found between subgroups of patients with suspected stable AP according to severity of CAD. ROC-analysis showed an AUC of 0.62 (95% CI: 0.57-0.67). The optimal cut-off value of OPG (<2.29 ng/mL) had a sensitivity of 56.2% (95% CI: 49.2-63.0%) and a specificity of 62.9% (95% CI: 57.3-68.2%).. OPG cannot be used to differentiate between healthy subjects with low versus high levels of coronary calcifications. In patients with suspected AP a single OPG measurement is of limited use in the diagnosis of CAD.

Topics: Angina Pectoris; Area Under Curve; Biomarkers; Calcinosis; Calcium; Comorbidity; Coronary Angiography; Coronary Artery Disease; Coronary Disease; Diabetes Mellitus; Female; Humans; Hyperlipidemias; Hypertension; Male; Middle Aged; Myocardial Infarction; Osteoprotegerin; ROC Curve; Sampling Studies; Severity of Illness Index; Smoking; Tomography, X-Ray Computed

Following the SEAS and SALTIRE studies in moderate-to-severe aortic stenosis (AS), it was postulated that the statin treatment had been initiated far too late during the disease course. Thus, the study aim was to assess the effect of four-week atorvastatin treatment (20 mg/day) on levels of calcification biomarkers in patients with early-stage disease (i.e., aortic sclerosis or mild AS).. In total, 33 patients (18 males, 15 females; mean age 70 +/- 8 years) with aortic sclerosis or mild AS, who had never received statin treatment, were enrolled into the study. According to their baseline lipid levels, 17 patients were hypercholesterolemic and 16 normocholesterolemic. Hence, rather than apply randomization, all patients were administered atorvastatin at a moderate dose level. Plasma levels of three biomarkers of calcification were measured, namely osteoprotegerin (OPG), osteopontin (OPN), and soluble receptor activator of nuclear factor (NF)-kappaB ligand (sRANKL).. Plasma levels of all three biomarkers were decreased after atorvastatin treatment. OPG levels fell from 13.23 +/- 5.33 to 10.92 +/- 5.34 pmol/l (p < 0.05), sRANKL from 105.36 +/- 69.47 to 86.74 +/- 71.36 ng/ml (p < 0.05), and OPN from 31.60 +/- 20.29 to 28.45 +/- 15.98 ng/ml (p = NS). When comparing patients with no/mild valvular calcification to those with moderate valvular calcification, only the OPG level before atorvastatin was statistically higher in patients from the latter group: 11.44 +/- 4.51 versus 16.09 +/- 5.67 pmol/l (p < 0.05).. Atorvastatin, at a dose level of 20 mg per day, reduced the plasma levels of calcification biomarkers in patients with aortic sclerosis and mild AS. The pre-atorvastatin OPG level was significantly higher when the aortic valve was moderately calcified, despite a persistent low transvalvular gradient.

Topics: Aged; Aortic Valve Stenosis; Atorvastatin; Biomarkers; Calcinosis; Down-Regulation; Drug Administration Schedule; Echocardiography, Doppler; Female; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Middle Aged; Osteopontin; Osteoprotegerin; Poland; Pyrroles; RANK Ligand; Sclerosis; Severity of Illness Index; Time Factors; Treatment Outcome

Coronary artery calcification (CAC) is an independent predictor of cardiovascular disease. A preventive role for vitamin K in CAC progression has been proposed on the basis of the properties of matrix Gla protein (MGP) as a vitamin K-dependent calcification inhibitor.. The objective was to determine the effect of phylloquinone (vitamin K1) supplementation on CAC progression in older men and women.. CAC was measured at baseline and after 3 y of follow-up in 388 healthy men and postmenopausal women; 200 received a multivitamin with 500 microg phylloquinone/d (treatment), and 188 received a multivitamin alone (control).. In an intention-to-treat analysis, there was no difference in CAC progression between the phylloquinone group and the control group; the mean (+/-SEM) changes in Agatston scores were 27 +/- 6 and 37 +/- 7, respectively. In a subgroup analysis of participants who were > or =85% adherent to supplementation (n = 367), there was less CAC progression in the phylloquinone group than in the control group (P = 0.03). Of those with preexisting CAC (Agatston score > 10), those who received phylloquinone supplements had 6% less progression than did those who received the multivitamin alone (P = 0.04). Phylloquinone-associated decreases in CAC progression were independent of changes in serum MGP. MGP carboxylation status was not determined.. Phylloquinone supplementation slows the progression of CAC in healthy older adults with preexisting CAC, independent of its effect on total MGP concentrations. Because our data are hypothesis-generating, further studies are warranted to clarify this mechanism. This trial was registered at clinicaltrials.gov as NCT00183001.

Topics: Aged; C-Reactive Protein; Calcinosis; Calcium; Calcium-Binding Proteins; Coronary Angiography; Coronary Vessels; Dietary Supplements; Double-Blind Method; Extracellular Matrix Proteins; Female; Humans; Interleukin-6; Male; Matrix Gla Protein; Middle Aged; Osteoprotegerin; Postmenopause; Vitamin K; Vitamins

Carotid plaque echogenicity quantified by the Gray-Scale Median (GSM) score has been associated with plaque vulnerability. The aim of this study was to assess whether intensive lipid-lowering treatment with atorvastatin in patients with carotid artery stenosis ameliorates novel vascular calcification inhibitors, such as osteopontin (OPN) and osteoprotegerin (OPG), and improves GSM score.. Ninety-seven patients with carotid stenosis (>40%), but without indication for intervention, were treated for 6 months with atorvastatin (10mg-80mg) to target LDL<100mg/dl. Fifty-two age-and sex-matched healthy individuals served as the control group. Blood samples and GSM were obtained at the beginning and after 6 months.. Systolic blood pressure, hsCRP, fibrinogen, OPN and OPG levels differed significantly between patients with carotid stenosis and healthy controls at baseline (p<0.05). Atorvastatin treatment improved lipid profile and significantly reduced hsCRP (p=0.002), WBC count (p=0.041), OPN (p<0.001) and OPG levels (p<0.001). GSM score increased considerably after atorvastatin therapy (from 58.33+/-24.38 to 79.33+/-22.3; p<0.001) and that effect appeared related to OPN (p=0.001), OPG (p=0.013) and LDL (p=0.01) reduction.. In patients with carotid stenosis, intensive lipid-lowering therapy with statins attenuates serum OPN and OPG levels and enhances carotid plaque echogenicity, outlining their beneficial effects on plaque stability.

Topics: Aged; Atorvastatin; Biomarkers; Blood Pressure; C-Reactive Protein; Calcinosis; Carotid Stenosis; Female; Fibrinogen; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Leukocyte Count; Male; Middle Aged; Osteopontin; Osteoprotegerin; Prospective Studies; Pyrroles; Severity of Illness Index; Treatment Outcome; Ultrasonography

To study the mechanism by which the readthrough mutation in TNFRSF11B, encoding osteoprotegerin (OPG) with additional 19 amino acids at its C-terminus (OPG-XL), causes the characteristic bidirectional phenotype of subchondral bone turnover accompanied by cartilage mineralization in chondrocalcinosis patients.. OPG-XL was studied by human induced pluripotent stem cells expressing OPG-XL and two isogenic CRISPR/Cas9-corrected controls in cartilage and bone organoids. Osteoclastogenesis was studied with monocytes from OPG-XL carriers and matched healthy controls followed by gene expression characterization. Dual energy X-ray absorptiometry scans and MRI analyses were used to characterize the phenotype of carriers and non-carriers of the mutation.. Human OPG-XL carriers relative to sex- and age-matched controls showed, after an initial delay, large active osteoclasts with high number of nuclei. By employing hiPSCs expressing OPG-XL and isogenic CRISPR/Cas9-corrected controls to established cartilage and bone organoids, we demonstrated that expression of OPG-XL resulted in excessive fibrosis in cartilage and high mineralization in bone accompanied by marked downregulation of MGP, encoding matrix Gla protein, and upregulation of DIO2, encoding type 2 deiodinase, gene expression, respectively.. The readthrough mutation at CCAL1 locus in TNFRSF11B identifies an unknown role for OPG-XL in subchondral bone turnover and cartilage mineralization in humans via DIO2 and MGP functions. Previously, OPG-XL was shown to affect binding between RANKL and heparan sulphate (HS) resulting in loss of immobilized OPG-XL. Therefore, effects may be triggered by deficiency in the immobilization of OPG-XL Since the characteristic bidirectional pathophysiology of articular cartilage calcification accompanied by low subchondral bone mineralization is also a hallmark of OA pathophysiology, our results are likely extrapolated to common arthropathies.

Topics: Bone Remodeling; Calcinosis; Cartilage, Articular; Chondrocalcinosis; Humans; Induced Pluripotent Stem Cells; Mutation; Osteoprotegerin; RANK Ligand

We aimed to investigate the factors affecting the development of atherosclerosis and the role of calcification inhibitors fetuin-A, matrix-Gla protein (MGP), osteoprotegerin (OPG) in atherosclerosis progress.. The study was planned to investigate the relationship of serum OPG, MGP and fetuin-A levels with the development of atherosclerosis in the stage 2-3-4-5 chronic kidney disease (CKD) patients who did not require dialysis treatment.. 32 (17 female, 15 male) healthy individuals and 92 (49 females, 43 males) CKD patients were included. The mean carotid intima-media thickness (CIMT), C-reactive protein (CRP), fetuin-A, OPG and MGP of the two groups were compared statistically. In CKD patients, age, body mass index (BMI), CRP, triglyceride, urea, systolic blood pressure (SBP), fasting blood sugar have a positive linear relationship, fetuin-A, OPG, GFR have a negative linear relationship with CIMT. The mean CIMT, right CIMT, left CIMT, blood urea, CRP, urinary albumin excretion creatinine and age show a negative linear relationship with fetuin-A.. Fetuin-A levels begin to decline from the early stages of CKD and are significantly lower in patients with atherosclerosis as expressed with CIMT. This suggests that fetuin-A may be used as an early marker in CKD for increased cardiovascular risk. Early recognition of these risk factors is important and large-scale studies on vascular calcification inhibitors are needed.

Topics: Adult; alpha-2-HS-Glycoprotein; Atherosclerosis; Biomarkers; C-Reactive Protein; Calcinosis; Carotid Intima-Media Thickness; Female; Humans; Linear Models; Male; Middle Aged; Osteoprotegerin; Renal Insufficiency, Chronic

Aortic valve sclerosis is a highly prevalent, poorly characterized asymptomatic manifestation of calcific aortic valve disease and may represent a therapeutic target for disease mitigation. Human aortic valve cusps and blood were obtained from 333 patients undergoing cardiac surgery (

Topics: Aged; Aortic Valve; Aortic Valve Stenosis; Base Sequence; Biomarkers; Calcinosis; Case-Control Studies; Cell-Free Nucleic Acids; Extracellular Matrix; Female; Humans; Male; Middle Aged; Osteopontin; Osteoprotegerin; RNA-Seq; RNA, Messenger; Transcriptome

Valve calcification commonly damages natural human heart valves and tissue-engineered heart valves (TEHVs), and no ideal intervention is available in clinical practice. It is increasingly considered that osteoprotegerin (OPG) inhibits vascular calcification. Herein we aimed to explore whether free OPG-Fc fusion protein or coupled OPG-Fc on decellularized aortic valves attenuates calcification. Calcification of rat bone marrow-derived mesenchymal stromal cells (MSCs) was induced by osteogenic differentiation media, and the effects of free OPG-Fc or OPG-Fc coupled on the decellularized porcine aortic heart valve leaflet scaffolds by coupling agents 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) on calcification were observed. Mineralization of the extracellular matrix, alkaline phosphatase (ALP) activity, and expression of osteoblastic markers were assessed to determine the calcification kinetics. Our results indicated that the matrix calcium content and the ALP activity, as well as the mRNA expression levels of a bone morphogenetic protein-2 (BMP-2), osteopontin (OPN), and osteocalcin (OC), of the MSCs seeded on plates with free OPG-Fc or on the OPG-Fc-coupled scaffolds decreased compared with their control MSCs without coupled OPG-Fc. The results suggest that both free and immobilized OPG-Fc on the decellularized aortic valve scaffolds by EDC/NHS can attenuate the calcification of MSCs induced by osteogenic differentiation media, implying that OPG-Fc might be a new treatment or prevention strategy for the calcification of natural human heart valves and TEHVs in the future.

Topics: Animals; Aortic Valve; Calcinosis; Cells, Cultured; Cross-Linking Reagents; Heart Valve Prosthesis; Immunoglobulin Fc Fragments; Osteoprotegerin; Rats; Recombinant Fusion Proteins; Swine; Tissue Engineering; Tissue Scaffolds

Topics: Animals; Aortic Diseases; Apolipoproteins E; Atherosclerosis; Calcinosis; Cells, Cultured; Cholesterol, Dietary; Chondrogenesis; Diet, High-Fat; Dietary Fats; Gene Expression Regulation; Interleukin-6; Male; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NF-kappa B; Osteoprotegerin; Random Allocation; RANK Ligand; Toll-Like Receptor 2

Osteoprotegerin (OPG) is a tumor necrosis factor receptor super-family member. It specifically acts on bone by increasing bone mineral density and bone volume. Recent studies have evidenced its close relation to the development of atherosclerosis and plaque destabilization. Elevated OPG level has also been associated with the degree of coronary calcification in the general population and it has been considered to be a marker of coronary atherosclerosis.. The aim of this study was to determine the relation between OPG levels and Coronary Artery Calcification score (CACs) in Type 2 diabetic patients in comparison to healthy controls.. Our study included 45 type 2 diabetic patients (mean age 51.7 years; 51.1% male) without evidence of previous CVD and 45 healthy age and sex matched subjects as control. All participants were subjected to full history, full examination and lab investigations. Serum OPG concentration was measured by an enzyme-linked immunosorbent assay (ELISA) and CAC imaging was performed using non contrast Multi detector CT of the heart.. Significant CAC (<10 Agatston units) was seen in 23 patients (51.11 %). OPG was significantly high in diabetic patients in comparison to controls with mean 12.9±5.7 pmol/l in cases, and 8.6±0.5 pmol/l in controls (P value < 0.001). The Coronary Artery Calcification Score (CACS) was positively correlated with age and duration of diabetes. The OPG was positively correlated with age, fasting blood sugar and duration of diabetes. The CACS showed a significantly positive correlation with OPG.. Findings suggested that increasing in serum OPG was consistent with CAC and could be used for the early diagnosis of subclinical atherosclerosis.

Topics: Adult; Asymptomatic Diseases; Atherosclerosis; Biomarkers; Calcinosis; Case-Control Studies; Coronary Artery Disease; Coronary Vessels; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Early Diagnosis; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged; Multidetector Computed Tomography; Osteoprotegerin; Predictive Value of Tests; Severity of Illness Index

The mechanism of valve calcification that is the main cause of aortic stenosis formation and progression is not yet clear. In recent years, the role of the OPG/RANKL/RANK system is considered as one of possible variants of pathogenesis of valve calcification. In presented work the differences in OPG and sRANKL levels involved in the calcification processes in tissues of patients with severe aortic stenosis have been examined. The study was performed using three groups of patients: group 1 - patients with aortic stenosis, group 2 - patients with aortic aneurysm, and group 3 - patients with aortic stenosis and aortic dilatation. In patients with aortic stenosis, the level of RANKL was significantly higher, and the level of RANKL was higher in valve than in tissue. The negative correlation between aortic dilatation and RANKL level indicated the lack of RANKL influence on pathogenesis of aortic dilatation. The obtained data confirm the increased expression of RANKL in patients with aortic valve calcification. The results of this study confirm importance of the OPG/RANKL/RANK system in calcification in patients with aortic stenosis. Athough patients of all groups had comparable values of OPG (including patients with aortic dilatation), the RANKL level increased only in patients with aortic stenosis. This suggest involvement of some additional mechanisms influencing the increase of RANKL expression.. Mekhanizm kal'tsifikatsii klapana, iavliaiushchiĭsia osnovnoĭ prichinoĭ formirovaniia i posleduiushchego progressirovaniia aortal'nogo stenoza (AS), poka ne iasen. V poslednie gody odnim iz vozmozhnykh variantov patogeneza kal'tsifikatsii aortal'nogo klapana rassmatrivaiut rol' sistemy OPG/RANKL/RANK. V predstavlennoĭ rabote provedeno izuchenie razlichiĭ v urovniakh OPG i sRANKL, uchastvuiushchikh v protsessakh kal'tsifikatsii v tkaniakh patsientov s tiazhelym AS. Dannoe issledovanie provedeno kak u patsientov s AS, tak i u patsientov s dilatatsieĭ aorty i sochetaniem étikh dvukh zabolevaniĭ. Povyshennaia ékspressiia RANKL byla vyiavlena u patsientov s AS; pri étom ona byla vyshe v klapane, chem v tkani aorty. U patsientov s dilatatsieĭ aorty byla vyiavlena otritsatel'naia korreliatsionnaia sviaz' mezhdu dilatatsieĭ aorty i RANKL. Rezul'taty nastoiashchego issledovaniia podtverzhdaiut znachenie sistemy OPG/RANKL/RANK v kal'tsifikatsii u patsientov s AS. Odnako na fone sopostavimykh znacheniĭ OPG v sravnivaemykh podgruppakh, v tom chisle u patsientov s dilatatsieĭ aorty, povyshenie RANKL otmechalos' tol'ko u patsientov s AS, chto ukazyvaet na sushchestvovanie dopolnitel'nykh mekhanizmov, vliiaiushchikh na uvelichenie ékspressii RANKL.

Topics: Aortic Valve; Aortic Valve Stenosis; Calcinosis; Humans; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

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

Comparative in vitro study examined the osteogenic potential of interstitial cells of aortic valve obtained from the patients with aortic stenosis and from control recipients of orthotopic heart transplantation with intact aortic valve. The osteogenic inductors augmented mineralization of aortic valve interstitial cells (AVIC) in patients with aortic stenosis in comparison with the control level. Native AVIC culture of aortic stenosis patients demonstrated overexpression of osteopontin gene (OPN) and underexpression of osteoprotegerin gene (OPG) in comparison with control levels. In both groups, AVIC differentiation was associated with overexpression of RUNX2 and SPRY1 genes. In AVIC of aortic stenosis patients, expression of BMP2 gene was significantly greater than the control level. The study revealed an enhanced sensitivity of AVIC to osteogenic inductors in aortic stenosis patients, which indicates probable implication of OPN, OPG, and BMP2 genes in pathogenesis of aortic valve calcification.

Topics: Aged; Aortic Valve; Aortic Valve Stenosis; Ascorbic Acid; Bone Morphogenetic Protein 2; Calcinosis; Cell Differentiation; Core Binding Factor Alpha 1 Subunit; Dexamethasone; Female; Gene Expression Regulation; Glycerophosphates; Heart Transplantation; Humans; Male; Membrane Proteins; Middle Aged; Osteoblasts; Osteogenesis; Osteopontin; Osteoprotegerin; Phosphoproteins; Primary Cell Culture; Stromal Cells; Tricuspid Valve

Tartrate-resistant acid phosphatase (TRACP)-5b and osteoprotegerin (OPG) are specific and sensitive markers of bone resorption in patients with rheumatoid arthritis (RA) and chronic kidney disease (CKD). The TRACP-5b level is associated with the severity of RA and CKD, while the OPG level is associated with the severity of coronary atherosclerosis and calcification, and can predict a poor outcome in patients with coronary artery disease (CAD). However, the impact of TRACP-5b on coronary atherosclerosis in CAD patients remains unclear.. A total of 71 CAD patients (57 men, 14 women; mean age: 69.0±9.7 years) and 28 age- and gender- matched healthy subjects were investigated. The number of diseased vessels (a marker of the severity of coronary atherosclerosis) and the Gensini score (a marker of the extent of coronary atherosclerosis), as well as the OPG and TRACP-5b levels were measured in CAD patients. The TRACP-5b levels were classified into quartiles.. The TRACP-5b levels were significantly higher in CAD patients than in healthy subjects. Patients with higher TRACP-5b levels had higher OPG levels and Gensini scores than those with lower TRACP-5b levels. Higher TRACP-5b levels were associated with an increased number of diseased vessels. A multivariate linear regression analysis showed that the OPG level and the number of diseased vessels or the Gensini score were significantly and independently associated with the TRACP-5b level.. These data indicate that the TRACP-5b level is significantly associated with the OPG level and with the severity and extent of coronary atherosclerosis in CAD patients.

Topics: Aged; Arthritis, Rheumatoid; Biomarkers; Calcinosis; Case-Control Studies; Coronary Artery Disease; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Multivariate Analysis; Osteoprotegerin; Smoking; Tartrate-Resistant Acid Phosphatase; Treatment Outcome

This cross-sectional study was designed to assess the relationship between vascular stiffness (VS) and bone-related proteins involved in the development of arteriosclerosis in patients on regular hemodialysis (HD).. 68 consecutive patients in stable clinical condition who received regular HD in the FMC Dialysis Center, Pécs were included. VS parameters (carotid-femoral pulse wave velocity - PWV, aortic augmentation index - AIx) were determined by applanation tonometry (SphygmoCor, AtCor Medical, Sidney) and the routine latoratory test were completed with measurements of osteocalcin (OC), osteopontin (OP) and osteoprotegerin (OPG) by using commercially available ELISA kits. 35 heathcare workers served as controls.. In patients on regular HD PWV markedly increased and there was several-fold elevation in the interrelated bone-specific proteins (OC, OP, OPG). PWV was found to be independently associated only with OC (β:-0.25, p<0.029) and age (r=0.411,p<0.000), but risk factors for arterial calcification had significant impact on OC (systolic blood pressure, hsCRP, BMI), OPG (age, BMI) and OP (LDL-cholesterol).. Except for OC, our results failed to document direct association of vascular lesion with OP and OPG, therefore their high circulating levels may be an epiphenomenon or they may have counter-regulatory role to attenuate the uremic calcification process.

Topics: Adult; Aged; Calcinosis; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Osteocalcin; Osteopontin; Osteoprotegerin; Pulse Wave Analysis; Renal Dialysis; Vascular Stiffness

Calcific aortic valve disease is associated with inflammation and calcification, thus the osteoprotegerin (OPG), receptor activator of nuclear factor κB (RANK) and its ligand (RANKL) system involved in osteoclastogenesis and inflammation may play a significant role in valve degeneration.. The aim of this study was to assess whether circulating OPG, sRANKL, and other bone metabolism markers can predict the presence of osteoclasts in stenotic valves and to evaluate their impact on the mode of degeneration.. The study involved 60 patients with aortic stenosis who underwent valve replacement surgery and subsequently were divided into 2 groups: osteoclastic (n = 12) and nonosteoclastic (n = 48), according to the presence or absence of intravalvular osteoclasts. Before the surgery, we measured serum levels of OPG, sRANKL, osteocalcin, osteopontin, tumor necrosis factor α (TNF-α), interleukin (IL) 1β, and IL-6. Immunohistochemistry and morphometry were used to determine the extent of valve calcification, lipid accumulation, neovascularization, and the number and phenotype of macrophages.. Compared with the nonosteoclastic group, patients with intravalvular osteoclasts had lower levels of OPG (P = 0.0006) and TNF-α (P = 0.02) and less frequently had diabetes (P = 0.04). Their valves showed higher incidence of ossification (P = 0.002), higher total (P = 0.008) and M2 macrophage counts (P = 0.0002), increased neovascularization (P = 0.003), and lower accumulation of lipids (P = 0.04). They also showed a negative correlation between valve calcification and age (r = -0.79, P = 0.002), which was not observed in patients without osteoclasts. In a multivariate analysis, low circulating OPG levels and the absence of diabetes were predictors of intravalvular osteoclastic differentiation.. The presence of osteoclasts in stenotic valves associated with low circulating OPG levels and an enhanced proportion of M2 macrophages can represent a variant of calcific aortic valve disease with a specifically regulated calcification process.

Topics: Aged; Aortic Valve; Aortic Valve Stenosis; Calcinosis; Cytokines; Female; Humans; Male; Middle Aged; Osteoclasts; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Osteoprotegerin (OPG) is a kind of tumor necrosis factor, which is related to bone metabolism and vascular calcification. The increase of Osteoprotegerin concentration in serum is related to cardiovascular diseases in humans. The purpose of this study was to figure out the relevance between osteoprotegerin in serum and carotid calcification. Serum OPG concentrations were compared in 145 patients who underwent carotid sonography (average age: 68 ± 9 years old, male: female = 81:64). A calcified plaque (CP) (37 people [27%]), a noncalcified plaque (NCP) (54 people [37%]), and a nonplaque (NP) (54 people [37%]) were classified for this study. No significant differences among 3 groups were demonstrated in the distribution of age, diabetes, high blood pressure, and hyperlipidemia. Serum osteoprotegerin concentrations were significantly increased in CP group rather than NCP group or NP group; (median [interquartile range], 4016 [1410] vs 3210 [1802] pg/mL, P < 0.05 and 4016 [1410] vs 3204 [1754] pg/mL, P < 0.05). Serum osteoprotegerin concentrations did not indicate a significant difference between NCP Group or NP Group. This study had proved that patient group accompanied with carotid calcification in carotid artery disease had an increased serum OPG concentration, so it could consider that OPG plays an important function on calcification related to arteriosclerosis.

Topics: Age Factors; Aged; Biomarkers; Calcinosis; Carotid Intima-Media Thickness; Carotid Stenosis; Electrocardiography; Female; Humans; Male; Middle Aged; Osteoprotegerin; Retrospective Studies; Risk Factors; Sex Factors; Tomography, X-Ray Computed

This is the first study analyzing concomitantly osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL) polymorphisms and OPG/RANKL serum levels and their association with bone mineral density (BMD), vertebral fractures, and vascular aortic calcification in a cohort of 800 subjects in community-dwelling older individuals.. Osteoprotegerin (OPG) and RANKL play an important role in osteoclast activation and differentiation as well as in vascular calcification. At present, there are no studies of OPG or RANKL gene polymorphisms in Brazilian older populations. The aim of this study was to evaluate OPG/RANKL polymorphism and their association with vertebral fractures (VFs) and aortic calcification.. Eight hundred subjects (497 women/303 men) were genotyped for the OPG 1181G>C (rs2073618), 163C>T (rs3102735), 245T>G (rs3134069), and 209G>A (rs3134070) and RANKL A>G (rs2277438) single-nucleotide polymorphisms (SNPs). VFs were evaluated by spine radiography (Genant's method). Aortic calcification was quantified using Kauppila's method.. The isolated genotype analyses and single-allele frequency data showed association of OPG 163C, 245G, and 209A alleles with presence of VFs (P < 0.05). Multiple logistic regression of subjects with absence of VFs vs. those with VFs (grades II/III) revealed only OPG 209A homozygosity as a risk factor for higher-grade VFs (odds ratio (OR) = 4.17, 95 % CI 1.03-16.93, P = 0.046). Regarding aortic calcification, the isolated genotype analysis frequency data revealed a significant association of OPG 1181G, 163C, 245G, and 209A alleles with absent aortic calcification (P < 0.05). Multiple logistic regression data confirmed that the OPG 209A allele was protective for aortic calcification (OR = 0.63, 95 % CI 0.45-0.88, P = 0.007) and the OPG 1181C allele was a risk factor for aortic calcification (OR = 1.26, 95 % CI 1.00-1.58, P = 0.046).. This study showed that the OPG 209AA genotype was a risk factor for higher-grade VFs, the OPG 209A allele was protective for aortic calcification, and the OPG 1181C was a risk factor for aortic calcification, supporting the involvement of OPG polymorphisms in the analyzed phenotypes and the concept that the related pathogenesis is multifactorial.

Topics: Aged; Aging; Aorta; Bone Density; Brazil; Calcinosis; Female; Humans; Male; Osteoprotegerin; Polymorphism, Single Nucleotide; RANK Ligand; Spinal Fractures

Elevated fibroblast growth factor 23 (FGF23) levels are associated with cardiovascular mortality in patients with chronic kidney disease. However, both clinical and basic research have demonstrated conflicting evidence regarding the pathophysiological role of FGF23 in vascular calcification. The aim of this study was to determine the role of FGF23 in the osteoblastic gene expression in vascular smooth muscle cells (SMCs).. We transduce human aortic SMCs (HASMCs) expressing klotho and FGF receptors with the adenovirus expressing human FGF23 (Ad-FGF23). We observed significant decreases in the expression of osteoblast-marker genes including BMP2, BMP4, MSX2, RUNX2 and ALP, as well as reduced calcification. Notably, Ad-FGF23 increased mRNA and protein levels of osteoprotegerin (OPG), and human OPG promoter was activated by FGF23. Moreover, in HASMCs overexpressing klotho, FGF23 upregulated OPG expression, whereas depletion of klotho by siRNA attenuated FGF23-induced OPG expression. Furthermore, in 73 consecutive patients with type 2 diabetes mellitus undergoing cardiac computed tomography to determine coronary calcium scores (CCSs), serum FGF23 levels were positively correlated with OPG independent of phosphate and estimated glomerular filtration rate (eGFR, r = 0.65, p < 0.01). Serum FGF23 levels were significantly elevated in patients with high CCSs (≧100) compared to those with low CCSs (<100).. Our in vitro results indicate that FGF23 suppresses osteoblastic gene expression and induces OPG expression in HASMCs. Together with our cross-sectional clinical assessment, the present study lends support to our hypothesis that FGF23 counteracts osteogenic conversion of vascular SMCs as a part of a compensatory mechanism to mitigate vascular calcification.

Topics: Aorta; Calcinosis; Cell Movement; Cell Proliferation; Cells, Cultured; Cross-Sectional Studies; Extracellular Signal-Regulated MAP Kinases; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Gene Expression Profiling; Gene Expression Regulation; Glucuronidase; HeLa Cells; Humans; Klotho Proteins; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Osteoblasts; Osteoprotegerin; Phosphates; raf Kinases; Receptor, Fibroblast Growth Factor, Type 1; RNA, Small Interfering

To assess serum levels of the plaque calcification regulators osteoprotegerin (OPG) and Matrix Gla-proteins (MGP) in individuals with stable angina and acute myocardial infarction submitted to coronary angiography and their relation to coronary artery disease burden.. The study included 40 individuals affected by ST-elevation myocardial infarction (STEMI) and 40 individuals with stable angina who all underwent coronary angiography, with evaluation of the extent of coronary artery disease by Syntax Score calculation and measurement of serum OPG and MGP levels. Osteoporosis was excluded by femoral and vertebral computerized bone mineralometry.. Serum OPG and MGP levels were respectively 3.87 ± 1.07 pmol/l and 6.80 ± 2.43 nmol/l in the stable angina group, 7.57 ± 1.5 pmol/l and 7.18 ± 1.93 nmol/l in the STEMI group (P < 0.01 and P = 0.33, respectively). Pearson correlation coefficient for OPG and Syntax Score, MGP and Syntax score was respectively 0.79 (P < 0.01) and 0.18 (P = 0.22) in the stable angina group, -0.03 (P = 0.43) and 0.10 (P = 0.5) in the STEMI group.Serum OPG and MGP levels were respectively 5.52 ± 1.02 pmol/l and 7.56 ± 1.42 nmol/l in diabetics, 4.3 ± 0.8 pmol/l and 6.52 ± 1.14 nmol/l in nondiabetics (P < 0.05; P < 0.05).. OPG, in a relatively small group of patients with stable angina, correlates proportionally with the extent of coronary artery disease (CAD), as evaluated by the Syntax Score. Higher serum OPG levels can be observed in individuals with STEMI regardless of CAD burden. As for MGP, a potential role as marker of plaque calcification remains unproven.

Topics: Aged; Angina, Stable; Biomarkers; Bone Density; Calcinosis; Calcium-Binding Proteins; Coronary Angiography; Coronary Artery Disease; Diabetic Angiopathies; Extracellular Matrix Proteins; Humans; Male; Matrix Gla Protein; Middle Aged; Myocardial Infarction; Osteoprotegerin

To assess the osteoprotegerin (OPG) relationship with cardiovascular complications in hemodialysis (HD) patients.. The study included 87 HD patients. Clinical characteristics, ankle-arm index (AAI), OPG and mineral markers levels were recorded. Arterial intimal calcification (AIC) and arterial medial calcification (AMC) were registered.. OPG levels were increased in HD patients. Patients with AIC (p = 0.006)/ AMC (p = 0.01) had higher OPG levels. OPG did not have any relation with cardiovascular diseases. OPG correlated positively with age, increased HD vintage and inversely with albumin and AAI. OPG has not been a risk factor for VC or cardiovascular disease.. OPG rising could be a reaction in defense to vascular aggression, because OPG was associated with VC, but not with vascular disease.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Biomarkers; Blood Pressure; Calcinosis; Cardiovascular Diseases; Cross-Sectional Studies; Female; Humans; Kidney Failure, Chronic; Logistic Models; Male; Middle Aged; Osteoprotegerin; Prospective Studies; Renal Dialysis; Risk Factors; Tunica Intima; Tunica Media; Young Adult

Ectopic vascular calcification is a significant component of atherosclerotic disease. Osteopontin (OPN), Osteoprotegerin (OPG), Receptor Activator of NFκB Ligand (RANKL), and alkaline phosphatase (ALP) are each thought to play central roles in the calcification or demineralization of atherosclerotic lesions. Abnormalities in the balance of these proteins may lead to perturbations in bone remodeling and arterial calcification. The purpose of this study was to measure the distribution of these proteins in human carotid lesions and to elucidate possible mechanism(s) whereby they control the deposition or depletion of arterial calcification. Thirty-three patients who had undergone carotid endarterectomy (CEA) within the previous 18 months and 11 control patients were enrolled. CEA specimens were analyzed by EBCT for calcification content in terms of Agatston (AGAT) and Volume scores. CEA specimens were then cut into 5 mm segments which were homogenized and extracted. Extracts were analyzed for tissue levels of calcium, phosphorus, ALP, OPN, RANKL, and OPG. Fasting blood samples were analyzed for the same components. In CEA tissue segments, the calcification levels (CHA AGAT) were inversely associated with the levels of OPG (r = -0.432/-0.579, p < 0.05) and positively associated with the levels of RANKL (r = 0.332/0.415, p < 0.05). In turn, the tissue levels of OPG were associated with homologous serum levels of OPG (r = 0.820/0.389, p < 0.001), and the tissue levels of RANKL were associated with the serum levels of homologous RANKL (r = 0.739/0.666, p < 0.0001). This study suggests that serum levels of OPG and RANKL may be useful biomarkers for estimating the degree of calcification in carotid atherosclerotic lesions.

Topics: Aged; Aged, 80 and over; Alkaline Phosphatase; Biomarkers; Calcinosis; Carotid Arteries; Endarterectomy, Carotid; Female; Humans; Male; Middle Aged; Osteopontin; Osteoprotegerin; Plaque, Atherosclerotic; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

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

This study evaluates the relationship of blood osteoprotegerin (OPG) and receptor activator of nuclear κ-B ligand (RANKL) levels with coronary artery calcium (CAC) and cardiovascular risk factors in two studies of postmenopausal women. OPG, a marker of bone turnover, and its ligand, RANKL, may contribute to cardiovascular disease risk.. We tested the hypothesis that serum OPG and RANKL levels were associated with CAC and cardiovascular disease risk factors among postmenopausal women in the Women On the Move through Activity and Nutrition Study (WOMAN Study; n = 86; mean [SD], age 58 [2.9] y) and replicated our findings in the Healthy Women Study (HWS; n = 205; mean [SD] age, 61 [2.3] y). Serum OPG, total RANKL, and CAC were measured at baseline and 48 months in the WOMAN Study and on the eighth postmenopausal visit in the HWS.. In the WOMAN Study, higher OPG was associated with higher CAC, and higher total RANKL was associated with lower CAC and triglycerides. In the HWS, higher total RANKL was also associated with lower CAC and triglycerides. In logistic regression models adjusted for body mass index and triglycerides, the odds ratios (95% CIs) for CAC per unit increase in OPG were 1.78 (1.17-2.73) for the WOMAN Study and 1.02 (0.84-1.24) for the HWS, and the odds ratios (95% CIs) for CAC per unit increase in log total RANKL were 0.86 (0.64-1.17) for the WOMAN Study and 0.83 (0.72-0.96) for the HWS.. The inverse association of total RANKL with CAC and triglycerides is a new finding and may have important implications given the increasing use of drugs that modify total RANKL and its receptor, receptor activator of nuclear κ-B.

Topics: Biomarkers; Calcinosis; Coronary Artery Disease; Female; Humans; Middle Aged; Osteoprotegerin; Postmenopause; Predictive Value of Tests; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Risk Factors; Triglycerides

to compare blood serum levels of osteoprotegerin (OPG) and soluble receptor activator of nuclear factor B ligand (sRANKL) in patients with different morphological variants of stenosis.. We included in this study 57 patients with aortic stenosis: 29 with bicuspid aortic valve (BAV) and 28 with tricuspid aortic valve (TAV). Subjects without heart diseases (n=32) were also examined. In all patients we determined lipid profile and measured serum levels of C-reactive protein, OPG and sRANKL.. OPG levels were evaluated in all patients with aortic stenosis while evaluated sRANKL was found only in patients with BAV. Age and arterial hypertension were key risk factors for OPG/RANKL/RANK system activation.. Despite differences in pathogenesis of aortic stenosis in patients with BAV and TAV processes of calcification may have common mechanisms. The data obtained correspond to the conception of importance of OPG/RANKL/RANK system activation for development and progression of degenerative aortic stenosis.

Topics: Aortic Valve; Aortic Valve Stenosis; Biomarkers; C-Reactive Protein; Calcinosis; Echocardiography; Female; Humans; Hypertension; Lipids; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Risk Factors; Severity of Illness Index; Statistics as Topic

There are no rigorously confirmed effective medical therapies for calcific aortic stenosis. Hypercholesterolemic Ldlr (-/-) Apob (100/100) mice develop calcific aortic stenosis and valvular cardiomyopathy in old age. Osteoprotegerin (OPG) modulates calcification in bone and blood vessels, but its effect on valve calcification and valve function is not known.. To determine the impact of pharmacologic treatment with OPG upon aortic valve calcification and valve function in aortic stenosis-prone hypercholesterolemic Ldlr (-/-) Apob (100/100) mice.. Young Ldlr (-/-) Apob (100/100) mice (age 2 months) were fed a Western diet and received exogenous OPG or vehicle (N = 12 each) 3 times per week, until age 8 months. After echocardiographic evaluation of valve function, the aortic valve was evaluated histologically. Older Ldlr (-/-) Apob (100/100) mice were fed a Western diet beginning at age 2 months. OPG or vehicle (N = 12 each) was administered from 6 to 12 months of age, followed by echocardiographic evaluation of valve function, followed by histologic evaluation.. In Young Ldlr (-/-) Apob (100/100) mice, OPG significantly attenuated osteogenic transformation in the aortic valve, but did not affect lipid accumulation. In Older Ldlr (-/-) Apob (100/100) mice, OPG attenuated accumulation of the osteoblast-specific matrix protein osteocalcin by ∼80%, and attenuated aortic valve calcification by ∼ 70%. OPG also attenuated impairment of aortic valve function.. OPG attenuates pro-calcific processes in the aortic valve, and protects against impairment of aortic valve function in hypercholesterolemic aortic stenosis-prone Ldlr (-/-) Apob (100/100) mice.

Topics: Age Factors; Animals; Aortic Valve; Aortic Valve Stenosis; Apolipoprotein B-100; Calcinosis; Disease Models, Animal; Female; Hypercholesterolemia; Injections; Male; Mice; Mice, Transgenic; Osteogenesis; Osteoprotegerin; Receptors, LDL; Ultrasonography

The aim of the study was to assess the relationship between the advancement of secondary hyperparathyroidism and the concentrations of selected calcification markers, i.e. osteopontin (OPN), osteoprotegerin (OPG), osteocalcin (OC), fetuin-A as well as fibroblast growth factor-23 (FGF-23) in peritoneal dialysis patients (PD).. The study included 67 patients (36 male and 31 females) aged 52.9 years (19-75 years) with chronic kidney disease (CKD) on peritoneal dialysis therapy 30.4 +/- 24.2 months. BMI was calculated using Quetelet formula. Serum Pi, Ca, albumin, fibrinogen, iPTH were performed using standard laboratory methods, while the selected bone metabolism parameters: fetuin-A, OC, OPG, OPN and FGF-23 were measured based on commercially available ELISA kits.. Patients with high iPTH levels (> 300 pg/ml) had higher OC levels (median 68.5 ng/mL) comparing to patients with target iPTH, i.e. 100-300 pg/ mi (57.3 ng/mL; p = 0.003) and patients with low iPTH < 100 pg/ml (17.3 ng/mL; p < 0.0001). Also, OPN and FGF-23 concentrations were significantly higher in patients with high iPTH comparing to patients with target iPTH (1535 vs. 1001 ng/mL; p = 0.04 and 4952 vs. 702 RU/ mL; p = 0.02, respectively). Patients with increased Ca x P values (> 45 mg2/dl2) as compared with patients having lower Ca x P had higher FGF-23 (4308 vs. 678 RUlmL; p < 0.0001), higher OC (67.0 vs. 60.2 ng/mL; p = 0.049) and lower OPG concentrations (8.97 vs. 11.97 pmol/L; p = 0.02). OC strongly correlated with iPTH concentration (R = 0.78; p < 0.0001) and FGF-23 strongly correlated with Ca x P value (R = 0.74; p < 0.0001).. In peritoneal dialysis patients along with increment of IPTH concentrations and enchancement of calcium-phosphate imbalance, significantly rise concentrations of calcification markers such as: osteocalcin (OC), osteopontin (OPN), as well as fibroblast growth factor-23 (FGF-23).

Topics: Adult; Aged; alpha-2-HS-Glycoprotein; Biomarkers; Calcinosis; Calcium; Female; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Hyperparathyroidism, Secondary; Kidney Failure, Chronic; Male; Middle Aged; Osteocalcin; Osteopontin; Osteoprotegerin; Peritoneal Dialysis; Young Adult

Vascular calcification is a pathobiological process which leads to high morbidity and mortality in cardiovascular disease. The association between vascular calcification and osteoporosis has been reported widely, and there are close relationships among vascular calcification, related cardiovascular disease and osteoporosis, but the biochemical mechanism of vascular calcification is presently unclear. For exploring the possible mechanism of artery calcification we established aorta calcification in an animal model with vitamin D(3) and warfarin and tested the effect of alendronate on the expression of osteopontin and osteoprotegerin in calcified aorta tissue of the rat through measuring gene and protein expression of osteopontin and osteoprotegerin respectively. The results indicated compared with control group, the aortic calcium content of calcification group was obviously increased, osteopontin mRNA and osteoprotegerin mRNA were significantly reduced, and osteoprotegerin and osteopontin protein expressions were reduced. Compared with calcification group, the aortic calcium content of alendronate group was obviously reduced, osteopontin mRNA and osteoprotegerin mRNA were significantly increased, and osteopontin and osteoprotegerin protein expression were increased. We conclude that artery calcification may reduce the expression of osteopontin and osteoprotegerin. Alendronate may inhibit rat aorta calcification by up-regulating osteopontin and osteoprotegerin expression.

Topics: Alendronate; Animals; Aorta; Calcinosis; Calcium; Gene Expression Regulation; Male; Osteopontin; Osteoprotegerin; Rats; Rats, Sprague-Dawley

Recent works demonstrated the difference of calcification genesis between carotid and femoral plaques, femoral plaques being more calcified. It has been clearly demonstrated that the molecular triad osteoprotegerin (OPG)/Receptor Activator of NFkB (RANK)/RANK Ligand (RANKL) exerts its activities in the osteoimmunology and vascular system. The aim of this study was to determine their expression and their potential role in calcifications of the atheromatous plaques located in two different peripheral arterial beds, carotid and femoral. The expression of OPG, RANK and RANKL was analyzed by immunochemistry in 40 carotid and femoral samples. Blood OPG and RANKL were quantified using specific ELISA assays. OPG staining was more frequently observed in carotid than in femoral plaques, especially in lipid core. Its expression correlated with macrophage infiltration more abundantly observed in carotid specimens. Surprisingly, serum OPG concentration was significantly lower in carotid population compared to femoral population while RANK and RANKL were equally expressed in both arterial beds. Carotid plaques that are less rich in calcium than femoral specimens, express more frequently OPG, this expression being correlated with the abundance of macrophages in the lesions. These data strengthen the key role played by OPG in the differential calcification in carotid and femoral plaques.

Topics: Calcinosis; Carotid Arteries; Enzyme-Linked Immunosorbent Assay; Femoral Artery; Humans; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Osteoprotegerin (OPG) and fibroblast growth factor-23 (FGF23) are recognized as strong risk factors of vascular calcifications in non dialysis chronic kidney disease (ND-CKD) patients. The aim of this study was to investigate the relationships between FGF23, OPG, and coronary artery calcifications (CAC) in this population and to attempt identification of the most powerful biomarker of CAC: FGF23? OPG?. 195 ND-CKD patients (112 males/83 females, 70.8 [27.4-94.6] years) were enrolled in this cross-sectional study. All underwent chest multidetector computed tomography for CAC scoring. Vascular risk markers including FGF23 and OPG were measured. Logistic regression analyses were used to study the potential relationships between CAC and these markers. The fully adjusted-univariate analysis clearly showed high OPG (≥10.71 pmol/L) as the only variable significantly associated with moderate CAC ([100-400[) (OR = 2.73 [1.03;7.26]; p = 0.04). Such association failed to persist for CAC scoring higher than 400. Indeed, severe CAC was only associated with high phosphate fractional excretion (FEPO(4)) (≥38.71%) (OR = 5.47 [1.76;17.0]; p = 0.003) and high FGF23 (≥173.30 RU/mL) (OR = 5.40 [1.91;15.3]; p = 0.002). In addition, the risk to present severe CAC when FGF23 level was high was not significantly different when OPG was normal or high. Conversely, the risk to present moderate CAC when OPG level was high was not significantly different when FGF23 was normal or high.. Our results strongly suggest that OPG is associated to moderate CAC while FGF23 rather represents a biomarker of severe CAC in ND-CKD patients.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Calcinosis; Coronary Artery Disease; Cross-Sectional Studies; Female; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Kidney Failure, Chronic; Logistic Models; Male; Middle Aged; Osteoprotegerin; Renal Dialysis

Vascular calcification is highly correlated with cardiovascular disease (CVD) morbidity and mortality, and it is associated with inflammation. Receptor activator of NF-ĸB ligand (RANKL) inhibition in vivo has been shown to reduce vascular calcification in a mouse model of atherosclerosis. Therefore, we tested the hypothesis that RANKL regulates smooth muscle cell (SMC) calcification by modulating macrophage production of pro-calcific cytokines.. We used a bone marrow-derived macrophage (BMDM)/SMC co-culture system and examined the effects of RANKL on BMDM activation and SMC matrix calcification.. Treatment with RANKL alone did not stimulate SMC calcification induced by elevated phosphate. BMDMs differentiated with macrophage colony-stimulating factor and placed in co-culture with SMCs increased phosphate-induced SMC calcification. RANKL added to the BMDM/SMC co-cultures further enhanced SMC calcification. Treatment of BMDMs with RANKL resulted in increased expression of IL-6 and TNF-α. Thus, increased expression of these pro-calcific cytokines in macrophages may mediate RANKL-induced SMC calcification in a paracrine fashion. Addition of neutralizing IL-6 and TNF-α antibodies together with RANKL treatment significantly reduced the RANKL induction of SMC calcification.. RANKL activation of pro-inflammatory and pro-calcific pathways in macrophages may contribute to vascular calcification and inflammation.

Topics: Animals; Calcinosis; Coculture Techniques; Cytokines; Interleukin-6; Macrophages; Mice; Myocytes, Smooth Muscle; Osteoclasts; Osteoprotegerin; Phosphates; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Tumor Necrosis Factor-alpha

Topics: alpha-2-HS-Glycoprotein; Calcinosis; Calciphylaxis; Calcium-Binding Proteins; Extracellular Matrix Proteins; Humans; Kidney Function Tests; Male; Matrix Gla Protein; Osteoprotegerin; Vascular Diseases; Young Adult

Serum receptor activator of nuclear factor-κ B ligand and osteoprotegrin are mediated to vascular calcification in the general population. Our knowledge is very sparse in hemodialysis and renal transplant patients. Receptor activator of nuclear factor-κ B ligand, osteoprotegrin, intact parathyroid hormone, calcium, and phosphorus were measured in blood samples of 45 hemodialysis and 45 age-matched renal transplant patients. Osteoprotegrin (P = 0.001) and intact parathyroid hormone (P = 0.001) levels in the hemodialysis patients were higher than the renal transplant recipients. Osteoprotegrin had positive correlation with duration of dialysis and age in the hemodialysis (r = 0.88, P = 0.001 and r = 0.34, P = 0.02, respectively) and renal transplant patients (r = 0.92, P = 0.001 and r = 0.46, P = 0.001, respectively). Hemodialysis patients have higher osteoprotegrin levels than the renal transplant recipients. It may act as a protective factor for renal osteodystrophy or only as a secondary phenomenon of advanced renal failure.

Topics: Adult; Age Factors; Calcinosis; Calcium; Female; Humans; Kidney Transplantation; Male; Middle Aged; Osteoprotegerin; Parathyroid Hormone; Phosphorus; RANK Ligand; Renal Dialysis; Renal Insufficiency; Time Factors

The aim of this prospective cohort study was to evaluate the progression of coronary artery calcification (CAC), and atherosclerosis in hemodialysis (HD) patients and to relate them to novel biomarkers, i.e. serum osteoprotegerin (OPG) and fibroblast growth factor 23 (FGF-23).. Forty-seven HD patients were followed up for 30 months or until death. Intima media thickness (CCA-IMT), atherosclerotic plaques and CAC were assessed at baseline and after 30 months. Serum mineral parameters, lipids, OPG and plasma FGF-23 were also measured.. At baseline, 70% HD patients presented detectable CAC. The patients without calcification at baseline remained calcification free at 30 months and presented lower serum OPG and FGF-23 than those with CAC. A 64.4% progression of CAC was observed in all patients with CAC at baseline. In parallel, a 13% increase in CCA-IMT was found. Both ΔCAC and ΔCCA-IMT correlated positively with baseline and follow-up serum OPG. The patients who died had significantly higher baseline CAC and serum OPG.. The plasma level of OPG could serve as a surrogate marker of progression of atherosclerosis and calcification in patients with end-stage renal disease. Therefore, the serum OPG may be a candidate biomarker of cardiovascular complications and poor outcome among dialysis patients.

Topics: Adult; Aged; Atherosclerosis; Biomarkers; Calcinosis; Cohort Studies; Coronary Artery Disease; Disease Progression; Female; Fibroblast Growth Factor-23; Follow-Up Studies; Humans; Kidney Failure, Chronic; Male; Middle Aged; Osteoprotegerin; Predictive Value of Tests; Prospective Studies; Renal Dialysis

Osteoprotegerin (OPG), a member of the TNF receptor superfamily, was initially found to modulate bone mass by blocking osteoclast maturation and function. Rodent models have also revealed a role for OPG as an inhibitor of vascular calcification. However, the precise mode of how OPG blocks mineralization is unclear. In this study, OPG was found in an in vitro assay to significantly inhibit calcification of vascular smooth muscle cells (VSMC) induced by high calcium/phosphate (Ca/P) treatment (p=0.0063), although this effect was blunted at high OPG concentrations. By confocal microscopy, OPG was detected in VSMC in the Golgi, the same localization seen in osteoblasts, which express OPG in bone. Treatment of VSMC by minerals (Ca, P, or both) induced OPG mRNA expression as assessed by real-time quantitative PCR, and VSMC derived from atherosclerotic plaque material also exhibited higher OPG expression as compared to control cells (p<0.05). Furthermore, OPG was detected by Western blotting in matrix vesicles (MV), nanoparticles that are released by VSMC with the capacity to nucleate mineral. In atherosclerotic arteries, OPG colocalized immunohistochemically with annexin VI, a calcium-dependent membrane and phospholipid binding protein found in MV. Thus, the calcification inhibitor OPG is contained in crystallizing MV and has a biphasic effect on VSMC: physiologic concentrations inhibit calcification, whereas high concentrations commonly seen in patients with vascular disease have no effect. Like other calcification inhibitors, OPG may be specifically loaded into these nanoparticles to be deposited at remote sites, where it acts to inhibit calcification.

Topics: Calcification, Physiologic; Calcinosis; Calcium; Crystallization; Humans; Microscopy, Confocal; Muscle, Smooth; Muscle, Smooth, Vascular; Nanoparticles; Osteoprotegerin; Phosphorus; Plaque, Atherosclerotic

Vascular calcification is frequent in patients with chronic kidney disease. Osteoprotegerin (OPG, a soluble factor which blocks osteoclast differentiation) has recently been implicated in the genesis of vascular calcification. Given that OPG can bind the pro-apoptotic tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), we hypothesized that the TRAIL protein is involved in the formation of vascular calcification both in vitro and in vivo. Using an immunohistochemical approach, we evaluated TRAIL and OPG expression on aortic valves slides from non-uremic and uremic wild type and apolipoprotein knockout (Apo E(-/-) ) mice. We also tested the in vitro effects of TRAIL on cultured primary human vascular smooth muscle cells (hVSMC). We further assayed serum soluble TRAIL (sTRAIL) levels in hemodialysis patients and correlated them with vascular calcification scores. Our results demonstrated that: (i) TRAIL and OPG were expressed inside the atheroma plaque in non-uremic ApoE(-/-) mice, but not in wild type mice; and (ii) uremia enhanced the expression levels. TRAIL enhanced the phosphate-induced mineralization of hVSMCs in a dose-dependent manner. In clinical terms, we demonstrated that sTRAIL is depressed in the sera of hemodialysis patients, but was not correlated with vascular calcification. Our results suggest that TRAIL may be involved in the formation of vascular calcification in certain experimental settings; however, its role in chronic kidney disease patients requires further evaluation.

Topics: Aged; Animals; Apolipoproteins E; Calcinosis; Cells, Cultured; Chronic Disease; Disease Models, Animal; Female; Humans; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Muscle, Smooth, Vascular; Osteoprotegerin; Plaque, Atherosclerotic; Renal Dialysis; TNF-Related Apoptosis-Inducing Ligand; Uremia

Osteoprotegerin (OPG) inhibits vascular calcification in vitro, and OPG(-/-) mice develop vascular calcification. Insulin-like growth factor-1 (IGF1) signalling has been implicated in vascular smooth muscle cell (VSMC) survival; however, the role of IGF1-receptor (IGF1R) expression in calcification is unclear. We sought to determine whether the protective effects of OPG in vascular calcification were mediated by IGF1R.. Calcium-induced mineralization of VSMCs was blocked in cells expressing the IGF1R and by treatment with OPG. OPG induced IGF1R mRNA, protein, and transcription optimally at 1 ng/mL. Calcium also positively regulated both OPG and IGF1R, and siRNA targeting of OPG inhibited calcium-inducible IGF1R mRNA. Addition of calcium to VSMCs reduced camptothecin-stimulated apoptosis and increased expression of survival genes Bcl2 and nuclear factor-kappa B without altering levels of proliferation. Calcium's induction of IGF1R and OPG was dose and time dependent but was blunted at higher calcium doses. Calcium- and OPG-inducible IGF1R transcription occurred between -446 and -188 bp of the IGF1R promoter, and inducible-IGF1R expression was blocked by specificity protein-1 (Sp1) silencing studies. Furthermore, elevated IGF1R and OPG protein levels were present in calcified atherosclerotic tissue.. We have shown for the first time that IGF1R expression and activity via OPG can modulate VSMC calcification in vitro. We suggest a feedback mechanism: moderate calcium levels increase OPG, which then increases IGF1R to enhance VSMC survival and block calcification induced by calcium. In contrast, high calcium leads to inhibition of IGF1R expression and activity to stimulate VSMC calcification further.

Topics: Animals; Apoptosis; Calcinosis; Calcium; Camptothecin; Cells, Cultured; Feedback, Physiological; Gene Expression Regulation; Humans; Muscle, Smooth, Vascular; Mutation; Myocytes, Smooth Muscle; NF-kappa B; Osteoprotegerin; Proto-Oncogene Proteins c-bcl-2; Rats; Receptor, IGF Type 1; RNA Interference; RNA, Messenger; Sp1 Transcription Factor; Time Factors; Transfection; Vascular Diseases

The receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) signaling pathway (RANKL/RANK/OPG signaling) is implicated in the osteolysis associated with diabetic Charcot neuroarthropathy (CN); however, the links with medial arterial calcification (MAC) seen in people with CN are unclear. This study aimed to investigate the role of RANKL/OPG in MAC in patients with CN.. Enzyme-linked immunosorbent assay and Bio-plex multiarray technology were used to quantify a range of cytokines, including RANKL and OPG in sera from 10 patients with diabetes, 12 patients with CN, and 5 healthy volunteers. Human tibial artery segments were immunohistochemically stained with Alizarin red and human RANKL antibody. Human vascular smooth muscle cells (VSMCs) were also explanted from arterial segments for in vitro studies.. We demonstrate colocalization and upregulation of RANKL expression in areas displaying MAC. Systemic levels of RANKL, OPG, and inflammatory cytokines (interleukin-8, granulocyte colony-stimulating factor) were elevated in those with CN compared with diabetic patients and healthy control subjects. Human VSMCs cultured in CN serum showed accelerated osteoblastic differentiation (alkaline phosphatase activity) and mineralization (alizarin red staining) compared with cells treated with diabetic or control serum (P < 0.05). Coincubation with OPG, the decoy receptor for RANKL, attenuated osteogenic differentiation of VSMCs and was independent of a high calcium-phosphate milieu. The accelerated mineralization induced by RANKL and CN serum correlated with nuclear translocation of nuclear factor-κB, a process abrogated by OPG.. Our data provide direct evidence that RANKL/RANK/OPG signaling is modulated in patients with CN and plays a role in vascular calcification. This study highlights this pathway as a potential target for intervention.

Topics: Aged; Calcinosis; Cell Differentiation; Cells, Cultured; Charcot-Marie-Tooth Disease; Diabetic Nephropathies; Female; Granulocyte Colony-Stimulating Factor; Humans; Interleukin-8; Male; Middle Aged; Muscle, Smooth, Vascular; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction

To determine whether differences exist in valvular high density lipoprotein (HDL) content between non-stenotic and stenotic aortic valves, and whether HDL could retard valvular calcification locally.. Stenotic aortic valves were obtained from valve replacement surgery and non-stenotic control valves from cardiac transplantations or at autopsy. The valvular localization and concentration of apolipoproteinA-I (apoA-I) were analyzed by immunohistochemistry and ELISA. The effects of HDL on the secretion of calcifying mediators and proinflammatory cytokines by cultured aortic valve myofibroblasts were assessed by ELISA and real-time PCR.. The concentration of apoA-I was higher in control than in stenotic valves (p < 0.05). ApoA-I surrounded the calcific deposits in stenotic valves, co-localizing with apoB, apoE, and osteoprotegerin (OPG). Incubation of cultured valve myofibroblasts with HDL increased their secretion of OPG (p < 0.001). Furthermore, incubation of myofibroblasts with HDL led to decreased mRNA expression of tumor necrosis factor alpha (TNF-α) (p < 0.05).. The amount of valvular HDL is reduced in aortic valve stenosis. HDL both induces the secretion of OPG and reduces the expression of TNF-α in vitro. Since OPG is known to inhibit and TNF-α to promote aortic valve calcification, HDL may have an anti-calcifying effect in human aortic valves.

Topics: Aortic Valve; Aortic Valve Stenosis; Apolipoprotein A-I; Apolipoproteins B; Apolipoproteins E; Autopsy; Calcinosis; Case-Control Studies; Cells, Cultured; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Finland; Heart Valve Prosthesis Implantation; Humans; Immunohistochemistry; Inflammation Mediators; Lipoproteins, HDL; Myofibroblasts; Osteoprotegerin; Real-Time Polymerase Chain Reaction; RNA, Messenger; Severity of Illness Index; Time Factors; Tumor Necrosis Factor-alpha

Because T2DM increases the risk of coronary atherosclerosis and CAD and new noninvasive techniques to assess CVD risk have gained considerable popularity, it is important to know how these tools relate to each other. The aim of this study was to evaluate the relationship between the extent of coronary artery calcification measured by MDCT, plasma OPG levels, baPWV and the established cardiovascular risk factors in Korean patients with T2DM. From November 2006 to December 2007, 110 asymptomatic Korean patients with T2DM without prior evidence of CAD were assessed (mean age 57.2 years). CAC imaging was performed using a 40-slice MDCT. Serum OPG levels were measured by an enzyme-linked immunosorbent assay (Oscotec, Korea) from the serum samples of each subject. We measured the baPWV as an index of arterial stiffness. In addition, we measured fasting glucose, HbA(1)C, hsCRP and lipid profiles. A total of 74 patients (67.3%) had minimal or insignificant CAC (<10). The CACS, OPG and baPWV showed significant positive correlations with each other. The CACS was significantly associated with the baPWV, smoking and use of a statin. The baPWV was significantly associated with age, duration of DM, total cholesterol and CACS by multiple linear regression models of the dependent variables of CACS or baPWV. CAC and baPWV were significant predictors of each other (r = 0.359, P = 0.014 and r = 0.361, P = 0.004). The results of this study showed that CAC, baPWV and serum OPG levels were significantly correlated with each other in asymptomatic Korean patients with T2DM. Furthermore, our results suggest that arterial stiffness, as determined by baPWV, may predict the extent of coronary calcification by MDCT.

Topics: Aged; Calcinosis; Coronary Artery Disease; Coronary Vessels; Diabetes Mellitus, Type 2; Humans; Male; Middle Aged; Osteoprotegerin; Republic of Korea; Vascular Resistance

The aim of the study was to assess the factors potentially involved in coronary artery calcifications (CAC) in end-stage renal disease patients. 253 hemodialysis (HD) patients (92 females, 161 males), aged 62.5 +/- 13.5, who had been on HD treatment for at least 6 months, were enrolled in a cross-sectional study. Calcium-phosphate product (Ca x P), body mass index (BMI), fetuin-A, osteoprotegerin (OPG), osteopontin, transforming growth factor-beta1 (TGF-beta1), fibroblast growth factor-23 (FGF-23) and matrix Gla protein (MGP) were considered. CAC was assessed using multislice spiral computed tomography and calcium score was quantified by means of the Agatston score. The median calcium score was 364 Agatston (range 0-7,336). CAC was detected in 228/253 patients (90.1%). Multivariate regression analysis, adjusted for age and for dialysis vintage, showed that TGF-beta1, OPG and days with Ca x P >55 mg/dl are independent predictors of CAC, while MGP was shown to be a protective factor. Surprisingly, results showed that BMI was a protective factor too: the interpolation with cubic spline function revealed a significant reduction in calcium score in patients with a high BMI (>28). However, when diabetes was considered in the regression analysis, only OPG emerged as a predictor of a high CAC score. The interpolation with spline function continued to show a significant reduction in CAC score in nondiabetic and in diabetic patients with the highest BMI quartile. The protective effect of a high BMI on CAC might represent another example of inverse biology in dialysis patients but it needs to be further addressed in larger longitudinal studies.

Topics: Adult; Aged; Body Mass Index; Calcinosis; Calcium; Cardiomyopathies; Cross-Sectional Studies; Diabetes Mellitus; Female; Fibroblast Growth Factor-23; Humans; Kidney Failure, Chronic; Male; Middle Aged; Osteoprotegerin; Transforming Growth Factor beta1

In symptomatic patients treated with ipsilateral carotid artery stenting (CAS) plus intensive lipid lowering, we assessed the changes of osteopontin (OPN), osteoprotegerin (OPG) and the Gray-Scale Median (GSM) score contralateral to symptomatic carotid stenosis.. Forty-six symptomatic patients (group A) with significant carotid stenosis (North American Symptomatic Carotid Endarterectomy Trial (NASCET): >70%) underwent ipsilateral CAS. Those patients had simultaneously contralateral low-grade carotid stenosis (NASCET: 30-69%). Group B included 67 symptomatic patients with low-grade bilateral carotid stenosis (NASCET: 30-69%), but without indications for revascularisation. All patients were treated with atorvastatin (10-80mg) to target low-density lipoprotein (LDL)<100mgdl(-1). Blood samples and plaques' GSM score contralateral to brain infarct were assayed at baseline and after 6 months.. At baseline, there were no significant differences between groups (p>0.05). Six-month atorvastatin treatment equivalently improved lipid profile in both groups (p<0.05). The parameters hsCRP, OPN and OPG were significantly down-regulated within both groups, but to a greater extent in group A (p<0.05). Besides this, contralateral GSM score was significantly improved from baseline in both groups (p<0.01), but that increment was more pronounced in group A (vs. group B; p=0.041). These changes were inversely correlated with changes in OPN (p=0.014), OPG (p=0.011) and LDL (p=0.041).. Ipsilateral CAS plus intensive lipid-lowering therapy was associated with enhanced contralateral carotid plaque stability and attenuated inflammatory burden and calcification inhibitors to a greater extent than atorvastatin therapy alone in patients with bilateral carotid stenosis.

Topics: Aged; Angioplasty; Atorvastatin; Biomarkers; C-Reactive Protein; Calcinosis; Carotid Stenosis; Combined Modality Therapy; Down-Regulation; Female; Greece; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Middle Aged; Osteopontin; Osteoprotegerin; Prospective Studies; Pyrroles; Severity of Illness Index; Stents; Time Factors; Treatment Outcome; Ultrasonography, Doppler

To assess the association of circulating bone marrow-derived osteo-progenitors with vascular calcification in mouse models and patients with peripheral artery disease.. We estimated the percentage of circulating mononuclear cells expressing osteocalcin in 2 mouse models of aortic calcification developed in osteoprotegerin-deficient mice (OPG(-/-)) using flow cytometry. Aortic calcification was assessed in mice principally by a bioassay of harvested aortas. In patients with peripheral artery disease osteocalcin-positive cells (estimated by flow cytometry) were related to aortic calcification volume assessed from computed tomography.. The amount of extractable aortic calcium was increased in both mouse models used in comparison to controls. The percentage of circulating mononuclear cells expressing osteocalcin was correlated to the amount of extractable aortic calcium in male (r=0.525, p=0.02) and female OPG(-/-) (r=0.564, p=0.02) mice and also in animals in which calcification was accelerated using calcitriol (r=0.64, p=0.01). Patients with more severe aortic calcification had a greater percentage of circulating OCN(+) MNCs (median 4.07%, IQR 3.76-4.39, n=12) than those with less severe aortic calcification (median 3.10%, IQR 2.32-3.60, n=11, p=0.05).. This study demonstrates that aortic calcification can be robustly quantified in 2 mouse models. In these models and patients with peripheral artery disease circulating osteocalcin positive mononuclear cells are associated with the severity of aortic calcification.

Topics: Animals; Aorta; Aortic Diseases; Calcinosis; Calcium; Disease Models, Animal; Female; Flow Cytometry; Humans; Leukocytes, Mononuclear; Male; Mice; Osteocalcin; Osteoprotegerin; Peripheral Vascular Diseases; Severity of Illness Index; Stem Cells; Tomography, X-Ray Computed

We investigated whether gene polymorphisms of Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and matrix metalloproteinase 3 (MMP3) are associated with increased vascular calcification in patients with type 2 diabetes (T2D) and evaluated whether serum MMP3 and osteoprotegerin (OPG) levels are related to calcification.. This study included 464 subjects: 269 patients with T2D and 195 healthy controls in South Korea. We genotyped subjects for four single nucleotide polymorphisms (SNPs): ENPP1 K121Q, ENPP1 A/G+1044TGA, MMP3 -709A>G and MMP3 -1475G>A. The presence or absence of calcifications in the aortic arch was assessed by plain chest radiography.. The SNPs ENPP1 K121Q and MMP3 -709A>G showed significant associations with T2D (P=0.001 and P=0.004). The SNP ENPP1 K121Q showed a significant association with aortic arch calcification in T2D (P=0.036). Serum OPG levels were significantly higher in T2D patients than in the control group (P<0.001). However, serum MMP3 levels were significantly lower in T2D patients than in the control group (P<0.001).. Our study demonstrates that the ENPP1 K121Q and MMP3 -709A>G polymorphisms are associated with T2D, and that the ENPP1 Q allele is associated with increased aortic arch calcification in a Korean population.

Topics: Adult; Aged; Alleles; Analysis of Variance; Aortic Diseases; Asian People; Body Composition; Calcinosis; Chi-Square Distribution; Diabetes Mellitus, Type 2; Diet; Female; Genetic Association Studies; Genetic Predisposition to Disease; Genetic Variation; Humans; Male; Matrix Metalloproteinase 3; Middle Aged; Osteoprotegerin; Phosphoric Diester Hydrolases; Polymorphism, Single Nucleotide; Pyrophosphatases; Regression Analysis; Republic of Korea

Coral reef aorta is a rare vascular disease with intraluminal calcifications of the dorsal part of the visceral aorta. The pathogenesis of this disease with its topographic and morphologic characteristics is unknown. The aim of our study was to investigate calcification inhibitors and the ultrastructure of calcifications in patients with coral reef aorta.. Ten patients with coral reef aorta were examined. Calcified specimens were investigated by immunohistochemical techniques for the expression of the calcification inhibitors matrix gla protein (MGP) and fetuin-A. Vessel walls were also assessed by electron microscopic techniques including electron energy-lost spectroscopy, electron dispersive spectroscopy, and electron diffraction. Sera of patients were analyzed for fetuin-A, uncarboxylated MGP (ucMGP), and osteoprotegerin.. As assessed by immunohistochemistry, most MGP was detected in the vicinity of calcified regions. Serum levels of the calcification inhibitors ucMGP, fetuin-A, and osteoprotegerin were 370+/-107 nmol/L, 0.57+/-0.03 g/L, and 5.64+/-0.79 pmol/L, respectively. Ultrastructural analysis of calcified specimens showed a core-shell structure with multiple calcification nuclei. Calcifications displayed a fine-crystalline character, and elemental analysis revealed hydroxyl apatite as the chemical compound.. The coral reef aorta represents an extreme exophytic growth of vascular calcification with multiple nuclei which resemble typical media calcification. Positive vascular immunostaining and low serum levels of both fetuin-A and ucMGP suggest a pathophysiologic role of these calcification inhibitors in the development of coral reef aorta.

Topics: Adult; Aged; alpha-2-HS-Glycoprotein; Aorta; Aortic Diseases; Aortography; Biomarkers; Blood Proteins; Calcinosis; Calcium-Binding Proteins; Durapatite; Extracellular Matrix Proteins; Female; Humans; Immunohistochemistry; Male; Matrix Gla Protein; Microscopy, Electron, Scanning; Middle Aged; Osteoprotegerin; Prospective Studies; Retrospective Studies; Tomography, X-Ray Computed

The aim of this study was to investigate the relationship between RANKL gene polymorphisms and aortic calcification in Korean women. In 237 healthy Korean women, aortic calcification in thoracic and abdominal aorta was examined in simple radiologic method and lumbar spine and femoral neck BMD were examined by dual energy X-ray absorptiometry. Serum OPG levels, bone turnover markers, such as ALP levels and urine deoxypyridinoline levels, and urine calcium excretion were measured. Genotyping of two RANKL gene polymorphisms, rs2277438 and rs9594782, was performed by allelic discrimination using the 5' nuclease polymerase chain reaction assay. The subjects with CT/CC genotypes of the rs9594782 polymorphism had a 3.9 times higher risk of aortic calcification compared with TT genotype. This significance was significant even after adjustment for age, BMI, blood pressure, fasting plasma glucose, serum high and low-density lipoprotein cholesterol levels. Mean levels of urine deoxypyridinoline were significantly higher in the subjects with AG/GG genotypes of the rs2277438 polymorphism compared with AA genotype, and this significance was persistent even after adjustment for age and BMI. There were no associations of mean values for age, BMI, serum OPG and ALP levels, urine calcium excretion, and BMD with RANKL gene polymorphisms. The RANKL gene rs9594782 polymorphism was associated with aortic calcification in Korean women. Rs2277438 polymorphism showed significant association with urine deoxypyridinoline levels, a bone resorption marker. These results suggest its role on vascular calcification and bone metabolism in humans.

Topics: Amino Acids; Aorta; Asian People; Bone Density; Bone Resorption; Calcinosis; Calcium; Female; Femur Neck; Humans; Korea; Middle Aged; Osteoprotegerin; Polymorphism, Genetic; RANK Ligand

Experimental evidence identified the osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB (RANK)/RANK ligand (RANKL) pathway as a candidate system modulating vascular remodeling and cardiovascular disease (CVD).. Serum concentrations of OPG and RANKL were measured in 3250 Framingham Study participants (54% women, 61+/-9 years). During a mean follow-up of 4.6 years, 143 (of 3084 free of CVD at baseline) participants developed a first CVD event, and 235 died. In multivariable models, OPG was associated with increased hazards for incident CVD and mortality (hazard ratio, 1.27; 95% CI, 1.04 to 1.54; and hazard ratio, 1.25; 95% CI, 1.07 to 1.47, per 1-SD increment in log-OPG, respectively). Log-OPG was positively related to multiple CVD risk factors, including age, smoking, diabetes, systolic blood pressure, and prevalent CVD. In a subsample (n=1264), the prevalence of coronary artery calcification, measured by computed tomography, increased nonsignificantly with OPG quartiles. RANKL concentrations displayed inverse associations with multiple CVD risk factors, including smoking, diabetes, and antihypertensive treatment, and were not related to coronary artery calcification or incident CVD or mortality.. Our prospective data reinforce OPG as marker for CVD risk factor burden and predictor for CVD and mortality in the community.

Topics: Aged; Biomarkers; Calcinosis; Cardiovascular Diseases; Coronary Artery Disease; Female; Humans; Incidence; Logistic Models; Male; Middle Aged; Osteoprotegerin; Predictive Value of Tests; Proportional Hazards Models; Prospective Studies; RANK Ligand; Risk Assessment; Risk Factors; Time Factors; Tomography, X-Ray Computed

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

Topics: Biomarkers; Calcinosis; Cardiovascular Diseases; Coronary Artery Disease; Humans; Incidence; Osteoprotegerin; Predictive Value of Tests; RANK Ligand; Risk Assessment; Risk Factors; Time Factors

In degenerative intervertebral discs (IVDs) collagen type X expression and calcifications have been demonstrated, resembling advanced osteoarthritis (OA), which is associated with hypertrophic differentiation, characterized by the production of collagen type X, Runt-related transcription factor 2 (Runx2), osteoprotegerin (OPG), alkaline phosphatase (ALP) and calcifications.. The aim of this study was to determine if hypertrophic differentiation occurs during IVD degeneration.. IVDs from all Thompson degeneration grades were prepared for histology, extraction of nucleus pulposus (NP) and annulus fibrosis (AF) tissue (N=50) and micro-CT (N=27). The presence of collagen type X, OPG and Runx2 was determined by immunohistochemistry, with OPG levels also determined by Enzyme-linked immunosorbent assay (ELISA). The presence of calcification was determined by micro-CT, von Kossa and Alizarin Red staining.. Immunohistochemical staining for collagen type X, OPG, Runx2 appeared more intense in the NP of degenerative compared to healthy IVD samples. OPG levels correlated significantly with degeneration grade (NP: P<0.000; AF: P=0.002) and the number of microscopic calcifications (NP: P=0.002; AF: P=0.008). The extent of calcifications on micro-CT also correlated with degeneration grade (NP: P<0.001, AF: P=0.001) as did von Kossa staining (NP: P=0.015, AF: P=0.016). ALP staining was only incidentally seen in the transition zone of grades IV and V degenerated IVDs.. This study for the first time demonstrates that hypertrophic differentiation occurs during IVD degeneration, as shown by an increase in OPG levels, the presence of ALP activity, increased immunopositivity of Runx2 and collagen type X.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Calcinosis; Cell Differentiation; Child; Child, Preschool; Collagen Type X; Core Binding Factor Alpha 1 Subunit; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hypertrophy; Immunohistochemistry; Intervertebral Disc; Intervertebral Disc Degeneration; Male; Middle Aged; Osteoprotegerin; X-Ray Microtomography; Young Adult

Topics: Animals; Aortic Valve Stenosis; Aortitis; Calcinosis; Humans; Osteoprotegerin; RANK Ligand; Thromboplastin; von Willebrand Diseases

Vascular calcifications (VCs) are important predictors of cardiovascular mortality in patients with chronic kidney disease (CKD). We have shown previously that osteoprotegerin (OPG), a potential early biomarker for VC, was an independent predictor of mortality in CKD patients. The aim of our study was to follow longitudinally coronary and aortic VCs. VCs were measured using Siemens 16 detector CT in a group of predialysis and hemodialyzed patients before and after a follow-up of 4 years. Some of these patients were transplanted in the meantime. Renal function, calcium, phosphate, iPTH, hs-CRP (high sensitive protein C reactive), and OPG serum levels were also compared. VCs progressed in predialysis, hemodialyzed, and transplanted patients but the progression was not the same in all arterial beds. A progression of coronary calcifications was observed in predialysis and transplanted patients, while aortic calcifications worsened significantly only in hemodialyzed patients. OPG serum levels and hs-CRP were significantly lower among transplanted patients. We concluded that VC depends on the severity of the kidney disease. Transplanted patients are not protected from VC, yet their OPG serum levels were significantly lower, suggesting that there is no link between between OPG levels and severity of VC. Longer follow-up of these patients would be necessary to assess whether a decline in OPG correlates with better survival.

Topics: Adult; Aged; Aortic Diseases; Belgium; Biomarkers; Calcinosis; Coronary Artery Disease; Female; Humans; Kidney Diseases; Kidney Transplantation; Least-Squares Analysis; Linear Models; Longitudinal Studies; Male; Middle Aged; Osteoprotegerin; Prognosis; Renal Dialysis; Severity of Illness Index; Time Factors; Tomography, X-Ray Computed

Osteoprotegerin (OPG) inhibits interaction of the receptor-activator of nuclear factor-kappaB (RANK) ligand (RANKL) with its receptor RANK, which is expressed on osteoclasts. OPG appeared to accelerate vascular calcification in vitro by the inhibition of vascular osteoclast-like cells. On the contrary, early-onset arterial calcification was observed in OPG-deficient mice. We measured the coronary artery calcification score (CACS) and abdominal aortic calcification score (AAoCS) by multi-detector computed tomography in 30 pre-dialysis CKD patients (eGFR 20 mL/min on average). Biomarkers were measured, including serum OPG, soluble RANKL (sRANKL) and tartrate-resistant acid phosphatase (TRACP) -5b (the biomarker of osteoclasts independent of renal function). The median values of CACS and AAoCS were 54.4 and 1,088 Agatston units (AU), respectively. Serum OPG was increased and serum sRANKL was decreased. In a multivariate logistic regression analysis using CACS > or = 100 AU as the outcome variable, CACS was found to be positively correlated with serum corrected Ca x iP product and serum OPG, though it was not correlated with serum TRACP-5b. ROC curve analysis showed that the serum OPG cutoff value predicting CACS > or = 100 AU was 5.2 pmol/L (624 pg/mL). In a stepwise regression analysis, log (AAoCS + 1) was positively correlated with serum OPG alone, but it was not correlated with age, eGFR, serum albumin and bone alkaline phosphatase (BAP). No correlation was found between serum OPG and serum TRACP-5b. In conclusion, vascular calcification in pre-dialysis CKD patients was correlated with an increase in OPG, but was independent of serum TRACP-5b. The decrease in serum sRANKL may have been caused by the increase in OPG production.

Topics: Acid Phosphatase; Aorta, Abdominal; Aortic Diseases; Biomarkers; Calcinosis; Coronary Disease; Coronary Vessels; Dialysis; Female; Humans; Isoenzymes; Logistic Models; Male; Osteoclasts; Osteoprotegerin; RANK Ligand; Tartrate-Resistant Acid Phosphatase

Patients on hemodialysis (HD) frequently experience cardiovascular events associated with vascular calcification. We investigated the involvement of osteoprotegerin (OPG), an inhibitor of vascular calcification, in the incidence of cardiovascular events and mortality among new HD patients.. We conducted a prospective cohort study of the association of serum OPG levels with morbidity and mortality in subjects who became new HD patients between June 2000 and May 2006.. A total of 99 patients (age 58.9 +/- 14.6 years, 65 male, 34 female) were prospectively followed up for 41.5 +/- 20.2 months. During this period, 27 patients developed cardiovascular events and 12 died of causes related to cardiovascular disease. When divided into 2 groups according to OPG levels, the high OPG group showed a higher prevalence of cardiovascular morbidity and mortality compared with the low OPG group. Cox's proportional hazards analysis associated the new onset of cardiovascular events with the high OPG group (HR 2.88, 95% CI 1.09-7.62, p = 0.033). Furthermore, the high OPG group at the start of HD was significantly associated with older age, male gender and a high aortic calcification index.. Elevated levels of serum OPG in new HD patients may predict subsequent cardiovascular events.

Topics: Adult; Aged; Aged, 80 and over; Calcinosis; Cardiovascular Diseases; Cohort Studies; Female; Humans; Japan; Kaplan-Meier Estimate; Kidney Failure, Chronic; Logistic Models; Male; Middle Aged; Osteoprotegerin; Proportional Hazards Models; Renal Dialysis; Young Adult

Vascular calcification (VC) is commonly seen in patients with chronic kidney disease (CKD). Elevated levels of phosphate and parathormone (PTH) are considered nontraditional risk factors for VC. It has been shown that, in vitro, phosphate transforms vascular smooth muscle cells (VSMCs) into calcifying cells, evidenced by upregulated expression of runt-related transcription factor 2 (Runx2), whereas PTH is protective against VC. In addition, Runx2 has been detected in calcified arteries of CKD patients. However, the in vivo effect of phosphate and PTH on Runx2 expression remains unknown.. Wistar rats were submitted to parathyroidectomy, 5/6 nephrectomy (Nx) and continuous infusion of 1-34 rat PTH (at physiological or supraphysiological rates) or were sham-operated. Diets varied only in phosphate content, which was low (0.2%) or high (1.2%). Biochemical, histological, immunohistochemistry and immunofluorescence analyses were performed.. Nephrectomized animals receiving high-PTH infusion presented VC, regardless of the phosphate intake level. However, phosphate overload and normal PTH infusion induced phenotypic changes in VSMCs, as evidenced by upregulated aortic expression of Runx2. High-PTH infusion promoted histological changes in the expression of osteoprotegerin and type I collagen in calcified arteries.. Phosphate, by itself is a potential pathogenic factor for VC. It is of note that phosphate overload, even without VC, was associated with overexpression of Runx2 in VSMCs. The mineral imbalance often seen in patients with CKD should be corrected.

Topics: Animals; Aorta, Thoracic; Calcinosis; Collagen Type I; Core Binding Factor Alpha 1 Subunit; Disease Models, Animal; Male; Muscle, Smooth, Vascular; Nephrectomy; Osteoprotegerin; Parathyroid Hormone; Parathyroidectomy; Phenotype; Phosphorus; Phosphorus, Dietary; Rats; Rats, Wistar; Risk Factors; Uremia

Vascular calcification commonly associated with several pathologies and it has been suggested to be similar to bone mineralization. The axis RANKL-OPG (receptor activator of nuclear factor kappaB ligand-osteoprotegerin) finely controls bone turnover. RANKL has been suggested to increase vascular calcification, but direct evidence is missing. Thus, in the present work, we assess the effect of RANKL in vascular smooth muscle cell (VSMC) calcification. VSMCs incubated with RANKL showed a dose-dependent increase in calcification, which was abolished by coincubation with OPG. To test whether the effect was mediated by signaling to its receptor, knockdown of RANK was accomplished by short hairpin (sh)RNA. Indeed, cells lacking RANK showed no increases in vascular calcification when incubated with RANKL. To further elucidate the mechanism by which RANK activation increases calcification, we blocked both nuclear factor (NF)-kappaB activation pathways. Only IKKalpha inactivation inhibited calcification, pointing to an involvement of the alternative NF-kappaB activation pathway. Furthermore, RANKL addition increased bone morphogenetic protein (BMP)4 expression in VSMCs, and that increase disappeared in cells lacking RANK or IKKalpha. The increase in calcification was also blunted by Noggin, pointing to a mediation of BMP4 in the calcification induced by RANKL. Furthermore, in an in vivo model, the increase in vascular calcium content was parallel to an increase in RANKL and BMP4 expression, which was localized in calcified areas. However, blood levels of the ratio RANKL/OPG did not change. We conclude that RANKL increases vascular smooth muscle cell calcification by binding to RANK and increasing BMP4 production through activation of the alternative NF-kappaB pathway.

Topics: Animals; Aortic Diseases; Bone Morphogenetic Protein 4; Calcinosis; Calcitriol; Carrier Proteins; Cells, Cultured; Disease Models, Animal; I-kappa B Kinase; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nephrectomy; Osteoprotegerin; RANK Ligand; Rats; Rats, Sprague-Dawley; Receptor Activator of Nuclear Factor-kappa B; RNA Interference; RNA, Small Interfering; Signal Transduction

Topics: Animals; Bone Morphogenetic Protein 4; Bone Remodeling; Calcinosis; Humans; Muscle, Smooth, Vascular; Osteolysis; Osteoprotegerin; RANK Ligand; Rats; Receptor Activator of Nuclear Factor-kappa B; Signal Transduction; Vascular Diseases

Cardiovascular disease is the leading cause of death in the chronic kidney disease (CKD) population. The mechanisms of vascular damage are not fully understood. The objective of this study was to prospectively investigate the importance of novel mediators of vascular damage, in conjunction with vascular calcification (VC), on survival.. A total of 134 subjects [60 haemodialysis (HD), 28 peritoneal dialysis (PD) and 46 CKD stage 4] were studied. All survivors completed 40 months of follow-up. VC was measured using multi-slice spiral CT of the superficial femoral artery. Circulating osteoprotegerin (OPG), Fetuin-A and high sensitivity C-reactive protein (hs-CRP) were measured in addition to standard clinical biochemical analysis.. After a 40-month follow-up, 31 patients had died (27 men and 4 women). Of 31 subjects, 31 had evidence of significant VC. The majority of deaths were in the HD group (48%), 36% were PD subjects and 16% were CKD subjects. The outcome of interest was survival at the end of follow-up. Multivariate logistical regression analysis revealed male gender [OR 8.06 (1.34-48.450) P = 0.02], OPG >25 pmol/L [OR 5.31(1.35-20.88) P = 0.02] and hypoalbuminaemia [OR 0.26 (0.12-0.56) P < 0.01], were associated with increased odds of death.. We have previously reported that VC and low albumin predict death in CKD stages 4 and 5 over a 2-year follow-up period. These data show that OPG, independent of CRP, is also associated with a negative outcome. The mechanisms remain to be elucidated; however, it is likely that they are associated with vascular damage through mechanisms in addition to VC.

Topics: C-Reactive Protein; Calcinosis; Cause of Death; Chronic Disease; Female; Humans; Kidney Diseases; Male; Middle Aged; Osteoprotegerin; Prospective Studies; Severity of Illness Index; Survival Rate; Time Factors; Vascular Diseases

Vascular calcification is frequently accompanied by intima-media thickening, but the associations among these atherosclerotic features and bone-related peptides in diabetic patients are unclear. We enrolled 168 type 2 diabetic patients and 40 non-diabetic subjects consecutively admitted to our hospital. Mean intima-media thickness (mean-IMT) in common carotid arteries was measured by B-mode ultrasonography. Agatston coronary artery calcium score (CACS) was obtained using multidetector-row computed tomography (MDCT). Plasma bone-related peptides osteopontin and osteoprotegerin levels were measured. Diabetic patients had higher mean-IMT (p=0.0002) and log(CACS+1) (p<0.0001) and similar bone-related peptides compared to non-diabetic subjects. In diabetic patients classified into tertiles according to their CACS levels, those with the highest scores showed the highest mean-IMT (p=0.0004) and bone-related peptides (p<0.05) among the groups. log(CACS+1) and mean-IMT were associated (p<0.0001) and were positively correlated with osteopontin (p<0.01) and osteoprotegerin (p<0.01) in diabetic patients. Multivariate analyses revealed that the significant independent determinants of log(CACS+1) were age, duration of diabetes and osteopontin (p<0.0001) and those of mean-IMT were age, hypertension, osteopontin and osteoprotegerin (p<0.0001), respectively. We have demonstrated that vascular calcification in type 2 diabetic patients is frequently accompanied by intima-media thickening, and osteopontin may act as a vascular calcification inhibitor by increasing intima-media thickness.

Topics: Adult; Age of Onset; Aged; Atherosclerosis; Calcinosis; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Multivariate Analysis; Osteopontin; Osteoprotegerin; Tomography, X-Ray Computed

Expression of bone proteins resulting from transdifferentiation of vascular smooth muscle cells into osteoblasts suggests that vascular calcifications are a bioactive process. Osteoprotegerin (OPG) could play a key role in bone-vascular calcification imbalance and could be a marker of vascular calcification extent and progression. The purpose of this study was to evaluate relationships between vascular risk biomarkers (including classic risk factors and OPG) and coronary artery calcification (CAC) extent in chronic kidney disease (CKD) patients and to establish within the markers the appropriate cut-off value to predict CAC.. A total of 133 non-dialyzed CKD patients at various stages of kidney disease [75 males/58 females, median age: 69.9 (27.4-94.6)] were enrolled, excluding extrarenal replacement therapy patients. All underwent chest multidetector computed tomography for CAC scoring. Blood samples were collected for measurement of vascular risk markers (kidney disease, inflammation, nutrition, calcium phosphate and OPG). A potential relationship between CAC and these biological markers was investigated, and a receiver-operating characteristic (ROC) curve was designed thereafter to identify a cut-off value of involved markers that best predicted the presence of CAC.. After adjustment for age, diabetes, smoking and gender, among biological markers, only low-estimated glomerular filtration rate using Modification of Diet in Renal Disease [OR = 3.63 (1.10-12.02)], high FEPO(4) [OR = 3.99 (1.17-13.6)] and high OPG levels [OR = 8.54 (2.14-34.11)] were associated with the presence of CAC. A protective effect of 1.25(OH)(2) vitamin D [OR = 0.20 (0.05-0.79)] and LDL cholesterol [OR = 0.27 (0.08-0.94)] on CAC was also observed. ROC curve analysis showed that the OPG best cut-off value predicting CAC was 757.7 pg/mL.. These results suggest that a CAC increase is strongly associated with a plasma OPG increase in CKD patients. The values of OPG >757.7 pg/mL allow us to predict the presence of CAC in these patients.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Calcinosis; Chronic Disease; Coronary Artery Disease; Female; Glomerular Filtration Rate; Humans; Kidney Diseases; Male; Middle Aged; Osteoprotegerin; Predictive Value of Tests; Risk Factors; ROC Curve

Topics: Calcinosis; Humans; Osteoprotegerin; Receptor Activator of Nuclear Factor-kappa B; Vascular Diseases

We prospectively assessed the evolution of coronary artery calcification (CAC) and osteoprotegerin (OPG) levels after renal transplantation (RT). Eighty-three recipients were followed-up prospectively during 1 year. Blood was collected before (baseline) and after RT for determination of mineral metabolism parameters including OPG. CAC was measured by multidetector computed tomography at transplantation (baseline) and 1 year later. Progression of CAC was defined as a difference between the follow-up square-root transformed volume (SRV) and the baseline SRV >or= 2.5. By multivariate analysis, baseline OPG level, age and low LDL levels were significantly associated with baseline CAC. RT was accompanied by mineral metabolism improvement with a decrease of OPG from 955 [395-5652] to 527 [217-1818] pg/mL and parathyroid hormone from 94 [1-550] to 62 [16-410] pg/mL. Thirty-one percent of patients did not exhibit CAC at baseline. CAC diminished in 14.5%, stabilized in 59.2% and progressed in 26.3% of patients. Baseline CAC was associated with progression (OR 2.92 [1.02-8.36]). No significant association was found between OPG and CAC progression despite a higher baseline OPG level in progressors (1046 [456-3285]) vs. non-progressors (899 [396-5952] pg/mL). CAC at baseline, but not 1 year after RT, is independently associated with baseline OPG; posttransplant CAC progression is predicted by baseline CAC score.

Topics: Adult; Aged; Calcinosis; Coronary Artery Disease; Disease Progression; Female; Follow-Up Studies; Humans; Kidney Failure, Chronic; Kidney Transplantation; Logistic Models; Male; Middle Aged; Multivariate Analysis; Osteoprotegerin; Parathyroid Hormone; Predictive Value of Tests; Prospective Studies; Risk Factors; ROC Curve; Young Adult

Although degenerative calcific aortic valve stenosis is the most common valvular disease among the elderly, neither the etiology underlying the condition nor degeneration of the bioprostheses is yet fully understood. The study aim was to assess the expression profile of those OPG/RANKL/RANK-system determinants known to act as key regulators of bone metabolism and the immune system in calcific aortic valve stenosis and porcine aortic bioprostheses.. Valve probes from a total of 69 patients (41 with end-stage aortic stenosis, 11 with mild-to-moderate aortic sclerosis, 17 with degenerative porcine aortic bioprostheses) were explanted either during surgery or at autopsy. The presence and localization of OPG, RANKL, RANK and NF-kappaB were analyzed by immunostaining and morphometry.. The majority of stenotic and sclerotic valves exhibited cell-bound signals of OPG, RANKL, RANK and NF-kappaB, while bioprostheses showed only sparse signaling. As key findings, the percentage of cells labeled by OPG, RANK and NF-kappaB was increased in sclerotic valves compared with stenotic valves (each p < 0.001), whereas the frequency of RANKL was higher in stenotic compared to sclerotic valves (p < 0.001). As a consequence, the OPG/RANKL ratio was decreased in stenotic (0.83) compared to sclerotic valves (20.2).. The differential expression profile of specific members of the OPG/RANKL/RANK axis suggests an involvement of their determinants in native valve calcification, but not in the degeneration of porcine bioprostheses. Thus, these mediators of bone homeostasis may represent new targets for a more specified prevention and/or therapy of native aortic stenosis.

Topics: Aged; Aortic Valve Stenosis; Bioprosthesis; Calcinosis; Female; Heart Valve Prosthesis; Humans; Immunohistochemistry; Male; Middle Aged; NF-kappa B; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Retrospective Studies

Topics: Animals; Atherosclerosis; Biomedical Research; Calcinosis; Humans; Mice; Osteoprotegerin; Receptors, LDL

Arterial calcification leading to increased arterial stiffness, a powerful risk factor for cardiovascular disease, may underlie the association of osteoporosis with cardiovascular disease in postmenopausal women. Osteoprotegerin (OPG), an indirect inhibitor of osteoclastogenesis, may be involved in arterial calcification. We examined relationships between calcification of subclinical atherosclerotic plaque and arterial stiffness with bone mineral density (BMD) and OPG in a group of 54 postmenopausal women referred for routine osteoporosis screening by dual-energy X-ray absorptiometric scanning of the lumbar spine and hip. Presence of calcified and noncalcified plaque in carotid and femoral arteries was examined using ultrasonography. Pulse wave velocity (PWV), a measure of arterial stiffness, was determined by sequential tonometry over the carotid and femoral region. Fifty-nine percent of osteoporotic women had calcified (echogenic) plaque at one or more sites compared with 42% and 20% for women with osteopenia and normal BMD, respectively (P = 0.04). There was a significant negative correlation between PWV and hip BMD (r = -0.35, P = 0.01), which remained significant when age, mean arterial pressure, and serum lipids were taken into account (P = 0.05). No significant relationships were observed between serum concentrations of OPG and lumbar spine or total hip BMD or with the number of arterial sites with calcified or noncalcified plaque. However, there was a strong correlation between OPG and PWV (r = 0.44, P = 0.001), which remained significant when adjusted for age (P = 0.01). These findings suggest that decreased BMD is associated with arterial calcification and stiffening and raise the possibility that OPG is a marker of arterial stiffening, independent of any association with BMD.

Topics: Adult; Aged; Aged, 80 and over; Atherosclerosis; Biomarkers; Bone Density; Calcinosis; Carotid Arteries; Female; Hip Joint; Humans; Lumbar Vertebrae; Mass Screening; Middle Aged; Osteoporosis, Postmenopausal; Osteoprotegerin; Radiography; Ultrasonography

Clinically, calcific aortic valve disease is a progressive continuum from obstructive fibro(sclero)tic valve thickening to aortic stenosis. Recent evidence suggests that, in addition to nonbone miscellaneous mineralization, calcified valves present distinct signs of active bone remodeling; and in this context, noncollagenous bone-associated proteins are assumed to have a critical role. The expression of 5 bone matrix proteins-bone morphogenetic protein-2 and -4, bone sialoprotein II, osteopontin, and osteoprotegerin-was examined by reverse transcriptase polymerase chain reaction (n = 31) and immunolabeling (n = 83) in the clinical continuum from healthy pliable valves to heavily calcified ones. As a known structural pathologic sign, the extent of neovascularization was also examined. We observed progressive increase in the gene expression of osteopontin (7.4-fold elevation, P < .001) and bone sialoprotein II (5.8-fold elevation, P < .05), and also 1.7-fold elevation (P < .05) in osteoprotegerin gene expression during the disease course. These findings were congruent with that of immunohistochemical analysis. Surprisingly, bone morphogenetic protein-2 and -4 showed a comparable significant decrease in messenger RNA levels in calcified valves (P < .01 and P < .05, respectively). Our results support the view that aortic valve calcification is an actively regulated process. Furthermore, the results suggest that the expression of pro- and anticalcific noncollagenous bone-associated matrix proteins is altered during the disease continuum and that this imbalance may contribute to the pathology of calcific aortic valve disease.

Topics: Adult; Aged; Aged, 80 and over; Aortic Valve; Aortic Valve Stenosis; Bone Morphogenetic Protein 2; Bone Morphogenetic Protein 4; Bone Morphogenetic Proteins; Calcinosis; Cardiomyopathies; Female; Gene Expression Regulation; Humans; Immunohistochemistry; Integrin-Binding Sialoprotein; Male; Middle Aged; Neovascularization, Pathologic; Osteopontin; Osteoprotegerin; Sialoglycoproteins

Although cardiovascular disease is a principal cause of death in patients with chronic kidney disease (CKD), it is often asymptomatic in diabetic patients. The coronary artery calcification score (CACS) measured by multidetector computed tomography (MDCT) is useful for screening ischemic heart disease in the general population. We investigated which clinical parameters predict high CACS in predialysis diabetic nephropathy (DN). Participants were 85 patients with DN. Nobody had any history of coronary angioplasty or coronary bypass surgery. We measured blood counts, blood chemistry, bone alkaline phosphatase, intact-PTH, interleukin-6, osteoprotegerin (OPG), hemoglobin A1c, 25-hydroxyvitamin D (25(OH)D) and fetuin-A. CACS and bone mineral density (BMD) were measured by a single 16-slice MDCT and DEXA, respectively. The median value of CACS equaled 256 Agatston units (range 0-4494 units). Stepwise increase in CACS with CKD stage progression was observed (p<0.01 for trend). Simple regression analyses showed that Log (CACS+1) was positively correlated with age, systolic blood pressure, phosphorus and OPG. In addition, it was negatively correlated with nutritional parameters, such as body mass index, albumin, total-cholesterol and 25(OH)D. Fetuin-A and BMD had no impact on CACS. Multiple regression analyses showed that low albumin and high OPG were associated with high CACS. The sensitivity of OPG for detecting CACS>200 was 80%, when the cut-off value was 1.2 ng/mL. In conclusion, CACS increased with CKD stage progression in predialysis DN patients. Serum OPG was positively associated with high CACS and can be a useful screening tool for severe coronary calcification, whereas no association between fetuin-A and CACS was found.

Topics: Adult; Aged; Aged, 80 and over; Calcinosis; Coronary Artery Disease; Cross-Sectional Studies; Diabetic Nephropathies; Female; Humans; Male; Middle Aged; Multivariate Analysis; Osteoprotegerin; Renal Dialysis; Risk Factors

Macrophage-derived products are known to play a crucial role during atherogenesis and vascular calcification. Glucocorticoids (GC) are important modulators of immune cell functions, but their specific effects on macrophages behavior during plaque formation are not defined. The present study was therefore designed to investigate the effects of macrophage-specific deletion of the glucocorticoid receptor (GR(LysMCre)) on atherogenesis and vascular calcification in a hyperlipidemic mouse-model.. Bone marrow was isolated from GR(LysMCre) mice and wild-type controls (GR(flox)) and subsequently transplanted into lethally irradiated LDL-receptor-deficient mice. Animals were fed a Western-type diet for 15 or 24 weeks, and atherosclerotic lesions within the aortic sinus were evaluated. At both time points, no significant difference in serum lipid and corticosterone concentrations, atherosclerotic lesion size and macrophage-content within the lesions could be observed. However, GR(LysMCre) mice showed less calcification as well as a significant reduction of RANKL, BMP2, and Msx2 expression within the vasculature. In vitro studies using conditioned media from macrophages which had been stimulated with dexamethasone demonstrated a dose-dependent increase in calcium deposition by vascular smooth muscle cells.. This study demonstrates that macrophage-specific glucocorticoid receptor inactivation reduces vascular calcification without affecting atherosclerotic lesion size in LDL receptor-deficient mice.

Topics: Animals; Atherosclerosis; Bone Marrow Transplantation; Calcinosis; Calcium; Disease Models, Animal; Female; Glucocorticoids; Hyperlipidemias; Macrophages; Mice; Mice, Inbred C57BL; Mice, Knockout; Osteoprotegerin; RANK Ligand; Receptors, Glucocorticoid; Receptors, LDL; RNA, Messenger

Visceral obesity and aortic calcification are both associated with cardiovascular events. The purpose of this study was to examine if visceral obesity was associated with the severity of abdominal aortic calcification.. One hundred and forty eight patients with peripheral artery disease were assessed by CT angiography. The severity of infrarenal abdominal aortic calcification was measured using a validated technique. The size of the visceral and subcutaneous compartments was estimated from anthropometric measurements made from the same CT. Calcification and anthropometric measurements were compared with Spearman's correlation and multiple logistic regression (adjusting for age, gender, hypertension, diabetes, smoking and cholesterol).. The relative size of the visceral compartment estimated from CT diameter ratios was correlated with abdominal aortic calcification severity, r=0.27, p=0.001 and independently associated with calcification allowing for other cardiovascular risk factors (OR 6.63, 95% CI 1.90-23.14). The relative size of the visceral compartment was associated with serum osteoprotegerin levels, suggesting a possible mechanism underlying the detrimental influence of visceral adiposity.. The association of visceral adiposity and arterial calcification suggests one mechanism, which may contribute to the detrimental effects of central obesity.

Topics: Adipokines; Aged; Angiography; Anthropometry; Aorta, Abdominal; Aortic Diseases; Calcinosis; Cohort Studies; Female; Humans; Intra-Abdominal Fat; Logistic Models; Male; Middle Aged; Obesity; Osteoprotegerin; Risk Factors; Severity of Illness Index; Tomography, X-Ray Computed

The role of osteoprotegerin in vascular disease is unclear. Recent observational studies show that serum osteoprotegerin levels are associated with the severity and progression of coronary artery disease, atherosclerosis, and vascular calcification in patients. However, genetic and treatment studies in mice suggest that osteoprotegerin may protect against vascular calcification.. To test whether osteoprotegerin induces or prevents vascular disease, we treated atherogenic diet-fed ldlr(-/-) mice with recombinant osteoprotegerin (Fc-OPG) or vehicle for 5 months. Vehicle-treated mice developed significant, progressive atherosclerosis with increased plasma osteoprotegerin levels, consistent with observational studies, and approximately 15% of these atherosclerotic lesions developed calcified cartilage-like metaplasia. Treatment with Fc-OPG significantly reduced the calcified lesion area without affecting atherosclerotic lesion size or number, vascular cytokines, or plasma cholesterol levels. Treatment also significantly reduced tissue levels of aortic osteocalcin, a marker of mineralization.. These data support a role for osteoprotegerin in the vasculature as an inhibitor of calcification and a marker, rather than a mediator, of atherosclerosis.

Topics: Animals; Aorta; Atherosclerosis; Calcinosis; Endothelium, Vascular; Mice; Mice, Knockout; Osteoprotegerin; RANK Ligand; Receptors, LDL; Recombinant Proteins; RNA, Messenger; Vascular Diseases

Arterial calcification is a phenotype of vascular repair in atherosclerosis, diabetes, hyperphosphatemic renal failure, and aging. Arterial calcification is modulated by transition of arterial smooth muscle cells (SMCs) from contractile to chondro-osseous differentiation programmed in response to increases in P(i), bone morphogenetic protein-2, and certain other stimuli. Transglutaminase (TG)2 release modulates tissue repair, partly by transamidation-catalyzed covalent crosslinking of extracellular matrix substrates. TG2 regulates cultured SMC differentiation, resistance artery remodeling to vasoconstriction, and atherosclerotic lesion size. Here, TG2 expression was required for the majority of TG activity in mouse and human aortic SMCs. TG2(-/-) SMCs lost the capacity for P(i) donor-induced formation of multicellular bone-like nodules and for increased expression of the type III sodium-dependent P(i) cotransporter Pit-1 and certain osteoblast and chondrocyte genes (tissue-nonspecific alkaline phosphatase, the osteoblast master transcription factor runx2, and chondrocyte-restricted aggrecan), and for P(i) donor- and bone morphogenetic protein-2-induced calcification. Uniquely in TG2(-/-) SMCs, P(i) donor treatment increased expression of the physiological SMC chondro-osseous differentiation and calcification inhibitors osteoprotegerin, matrix Gla protein, and osteopontin. Conversely, TG2(-/-) SMCs, unlike wild-type SMCs, failed to maintain contractile differentiation on laminin. Exogenous catalytically active TG2 augmented calcification by TG2(-/-) SMC in response to P(i) donor treatment. TG2 expression also drove P(i)-stimulated calcification of mouse aortic ring organ cultures, which was suppressed by the TG2 catalytic site-specific inhibitor Boc-DON-Gln-Ile-Val-OMe (10 micromol/L). Our results suggest that TG2 release in injured arteries is critical for programming chondro-osseous SMC differentiation and calcification in response to increased P(i) and bone morphogenetic protein-2.

Topics: Animals; Aorta; Arteries; Atherosclerosis; Calcinosis; Calcium-Binding Proteins; Cell Differentiation; Cells, Cultured; Extracellular Matrix Proteins; GTP-Binding Proteins; Humans; Laminin; Matrix Gla Protein; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Organ Culture Techniques; Osteopontin; Osteoprotegerin; Phosphates; Protein Glutamine gamma Glutamyltransferase 2; Transglutaminases

Accumulating evidence indicates that vascular and bone mineralization may be related, although the exact mechanism remains unknown.. Our objective was to investigate whether an observed inverse association between bone mineral density (BMD) and coronary artery calcification (CAC) in postmenopausal women currently taking estrogen therapy is mediated by osteoprotegerin (OPG) or receptor activator of nuclear factor-kappaB ligand (RANKL).. Participants were 92 postmenopausal women (aged 58-81 yr) taking estrogen therapy who had hip and spine BMD assessed by dual-energy x-ray absorptiometry and CAC measured by electron-beam computed tomography in 1998-2002 and serum RANKL and OPG levels measured in samples collected in 1997-1999. Total CAC score was dichotomized as none/minimal (10).. OPG serum levels were higher in women who had some CAC compared with those who had none/minimal (126.8 +/- 1.08 vs. 102.9 +/- 1.07 pg/ml, respectively, P = 0.03); these differences became nonsignificant after adjustment for age and other risk factors (P = 0.51). A 1 sd increase in hip BMD was associated with significantly lower odds of having CAC > 10 (odds ratio = 0.52; 95% confidence interval = 0.29-0.93) independent of age, fat-free mass, high-density lipoprotein cholesterol, current smoking, and use of cholesterol-lowering medications. Other skeletal sites demonstrated a similar pattern. Addition of RANKL and/or OPG to the model had minimal effect on the magnitude or statistical significance of the BMD-CAC association. Additionally, a test of interaction indicated that RANKL and OPG are not significant effect modifiers.. Serum OPG and RANKL do not account for the observed association between bone and coronary artery calcification among postmenopausal women using hormone therapy.

Topics: Aged; Aged, 80 and over; Bone Density; Calcinosis; Coronary Artery Disease; Estrogen Replacement Therapy; Female; Humans; Middle Aged; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Osteoprotegerin (OPG) is a marker and regulator of arterial calcification, and it is related to cardiovascular survival in haemodialysis patients. The link between OPG and aortic stiffening--a consequence of arterial calcification--has not been previously evaluated in this population, and it is not known whether OPG-related mortality risk is mediated by arterial stiffening.. At baseline, OPG and aortic pulse wave velocity (PWV) were measured in 98 chronic haemodialysis patients who were followed for a median of 24 months. The relationship between OPG and PWV was assessed by multivariate linear regression. The role of PWV in mediating OPG related cardiovascular mortality was evaluated by including both OPG and PWV in the same survival model.. At baseline mean (standard deviation) PWV was 11.2 (3.3) m/s and median OPG (interquartile range) was 11.1 (7.5-15.9) pmol/L. There was a strong, positive, linear relationship between PWV and lnOPG (P = 0.009, model R(2) = 0.540) independent of covariates. During follow-up 23 patients died of cardiovascular causes. In separate univariate survival models both PWV and lnOPG were related to cardiovascular mortality [hazard ratios 1.31 (1.14-1.50) and 8.96 (3.07-26.16), respectively]. When both PWV and lnOPG were entered into the same model, only lnOPG remained significantly associated with cardiovascular mortality [hazard ratio 1.11 (0.93-1.33) and 7.18 (1.89-27.25), respectively).. In haemodialysis patients OPG is strongly related to PWV and OPG related cardiovascular mortality risk is, in part, mediated by increased PWV.

Topics: Aged; Blood Flow Velocity; Calcinosis; Cardiovascular Diseases; Carotid Arteries; Cohort Studies; Female; Femoral Artery; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Models, Cardiovascular; Multivariate Analysis; Osteoprotegerin; Prospective Studies; Regional Blood Flow; Renal Dialysis; Risk Factors

Vascular calcification occurs in the majority of patients with chronic kidney disease, but a subset of patients does not develop calcification despite exposure to a similar uraemic environment. Physiological inhibitors of calcification, fetuin-A, osteoprotegerin (OPG) and undercarboxylated-matrix Gla protein (uc-MGP) may play a role in preventing the development and progression of ectopic calcification, but there are scarce and conflicting data from clinical studies.. We measured fetuin-A, OPG and uc-MGP in 61 children on dialysis and studied their associations with clinical, biochemical and vascular measures.. Fetuin-A and OPG were higher and uc-MGP lower in dialysis patients than controls. In controls, fetuin-A and OPG increased with age. Fetuin-A showed an inverse correlation with dialysis vintage (P = 0.0013), time-averaged serum phosphate (P = 0.03) and hs-CRP (P = 0.001). Aortic pulse wave velocity (PWV) and augmentation index showed a negative correlation with fetuin-A while a positive correlation was seen with PWV and OPG. Patients with calcification had lower fetuin-A and higher OPG than those without calcification. On multiple linear regression analysis Fetuin-A independently predicted aortic PWV (P = 0.004, beta = -0.45, model R(2) = 48%) and fetuin-A and OPG predicted cardiac calcification (P = 0.02, beta = -0.29 and P = 0.014, ss = 0.33, respectively, model R(2) = 32%).. This is the first study to define normal levels of the calcification inhibitors in children and show that fetuin-A and OPG are associated with increased vascular stiffness and calcification in children on dialysis. Higher levels of fetuin-A in children suggest a possible protective upregulation of fetuin-A in the early stages of exposure to the pro-calcific and pro-inflammatory uraemic environment.

Topics: Adolescent; alpha-2-HS-Glycoprotein; Blood Flow Velocity; Blood Proteins; Blood Vessels; Calcinosis; Calcium-Binding Proteins; Cardiovascular Diseases; Case-Control Studies; Child; Child, Preschool; Extracellular Matrix Proteins; Female; Humans; Kidney Failure, Chronic; Male; Matrix Gla Protein; Osteoprotegerin; Renal Dialysis

Arterial medial calcifications occur often in diabetic individuals as part of the diabetic macroangiopathy. The pathogenesis is unknown, but the presence of calcifications predicts risk of cardiovascular events. We examined the effects of insulin on calcifying smooth muscle cells in vitro and measured the expression of the bone-related molecule osteoprotegerin (OPG). Human vascular smooth muscle cells (VSMCs) were grown from aorta from kidney donors. Induction of calcification was performed with beta-glycerophosphate. The influence of insulin (200 microU/ml or 1,000 microU/ml) on calcification was judged by measuring calcium content in the cell layer and by von Kossa staining. OPG was measured in the medium by ELISA. Histochemistry was used for determination of alkaline phosphatase (ALP). Bone sialoprotein (BSP) and OPG mRNA expressions were done by RT-PCR. beta-Glycerophosphate was able to induce calcification in human smooth muscle cells from a series of donors after variable time in culture. Decreased OPG amounts were observed from the cells during the accelerated calcification phase. High dose of insulin (1,000 microU/ml) accelerated the calcification, whereas lower concentrations (200 microU/ml) did not. Calcified cells expressed ALP and BSP activity in high levels. In conclusion, high concentration of insulin enhances in vitro-induced calcification in VSMCs. Altered OPG levels during the calcification raise the possibility that OPG may have a potent function in regulating the calcification process or it may represent a consequence of mineralization. Effects of insulin and modulations by OPG on the calcification process in arterial cells may play a role in the development of calcifications as part of the diabetic macroangiopathy.

Topics: Alkaline Phosphatase; Aorta; Aortic Diseases; Calcinosis; Calcium; Cells, Cultured; Diabetic Angiopathies; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Glycerophosphates; Humans; Insulin; Integrin-Binding Sialoprotein; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Osteoprotegerin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sialoglycoproteins; Time Factors

Vascular calcifications in CKD are now linked to serum alterations of both divalent ions and calcification inhibitory proteins. Due to possible biochemical differences between dialysis (D) and transplantation (Tx), we examined the entity and severity of these biochemical modifications and of coronary artery calcium score separately in these two populations. We assayed, besides standard markers of inflammation, divalent ions and serum levels of fetuin, matrix Gla protein (MGP) and osteoprotegerin (OPG), in 51 Tx patients (age 45 +/- 12 years; 30 males, 21 females; previous D duration 4.8 +/- 4.2 years; Tx since 6.6 +/- 5.5 years; Cr 1.8 +/- 0.6 mg/dl) and in 49 D patients (age 49 +/- 14 years; 30 males,19 females; D duration 5.6 +/- 4.8 years). Additionally, coronary calcium score (AS) was evaluated by cardiac multi-slice CT. Compared with D patients, Tx patients had better values of divalent ions and inflammation markers, and lower prevalence (65 vs. 86%; p < 0.02) and severity (AS = 570 +/- 1,637 vs. 1,311 +/- 3,128; p < 0.008) of coronary calcification. In addition, a tendency toward normalization for all of the three calcification inhibitory proteins was evident. In both Tx and D, AS correlated with age and OPG (Tx: r(s) = 0.439, p < 0.001, and r(s) = 0.510, p < 0.0001; D: r(s) = 0.471, p < 0.001, and r(s) = 0.403, p < 0.005, respectively); in D patients, a correlation was present also with D duration (r(s) = 0.435; p < 0.002), other markers of inflammation and, notably, fetuin (r(s) = -0.442; p < 0.002). Regression analysis selected previous time on D in Tx patients (r(m) = 0.400; p < 0.004), and C-reactive protein and OPG in D patients (r(m) = 0.518; p < 0.004) as the most predictive parameters of AS. Discriminant analysis confirmed the major role of age and D duration in the appearance of AS and evidenced male gender as a distinct risk condition. At variance, Tx duration was never associated with AS. In conclusion, as compared to D, renal Tx patients show serum levels of calcification inhibition proteins and of divalent ions closer to normal. As this is associated with a lower prevalence and severity of AS, it is suggested that Tx antagonize the accelerating role of D in the progression of vascular calcification. Assessment of both coronary calcifications and serum levels of calcification inhibitory proteins may be of value to identify those subjects at higher risk of development and progression of vascular lesions, among whom males have the highest

Topics: 1-Carboxyglutamic Acid; alpha-Fetoproteins; Biomarkers; Calcinosis; Calcium; Calcium-Binding Proteins; Coronary Disease; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix Proteins; Female; Follow-Up Studies; Humans; Kidney Failure, Chronic; Kidney Transplantation; Male; Matrix Gla Protein; Middle Aged; Osteoprotegerin; Prognosis; Renal Dialysis; Severity of Illness Index; Tomography, X-Ray Computed

Circulating osteoprotegerin (OPG) has been shown to be elevated in patients with vascular disease. The role of OPG as a biomarker for atherosclerosis in a large, unselected population is not well known. Plasma OPG levels were measured in 3,386 subjects in the Dallas Heart Study, a multiethnic, population-based probability sample of adults aged 30 to 65 years. Coronary artery calcium (CAC) was measured by electron beam computed tomography. Aortic plaque was assessed by magnetic resonance imaging. Multivariable logistic regression was used to assess associations among OPG, cardiovascular risk factors, CAC, and aortic plaque. Age, female gender, black race, smoking, personal and family history of coronary artery disease (CAD), diabetes mellitus, hyperlipidemia, CAC, and aortic plaque were significantly associated with higher plasma OPG levels (p <0.01) in univariable analyses. The prevalence of CAC and aortic plaque increased across OPG quartiles (p <0.001 for each). An OPG level in the fourth quartile was independently associated with CAC (RR 1.39, 95% confidence interval 1.01 to 1.93) and aortic plaque (RR 1.42, 95% confidence interval 1.09 to 1.86) after adjustment for age, gender, smoking, diabetes, hyperlipidemia, and family history of premature CAD. In conclusion, plasma OPG is independently associated with CAC and aortic plaque in an unselected population, suggesting it may be a novel biomarker for atherosclerosis in humans.

Topics: Adult; Aged; Biomarkers; Calcinosis; Coronary Artery Disease; Coronary Vessels; Female; Humans; Logistic Models; Magnetic Resonance Imaging; Male; Middle Aged; Osteoprotegerin; Risk Factors; Texas; Tomography, X-Ray Computed

We tested the effects of calcitriol and its analog paricalcitol on VSMC calcification in vitro and in vivo. For that reason, cells and animals with five-sixths nephrectomy were treated with both compounds. Calcitriol, but not paricalcitol, increased VSMC calcification in vitro and in vivo independently of calcium and phosphate levels. This increase in calcification was parallel to an increase in the RANKL/OPG ratio.. Vascular calcification is a common finding in patients with endstage renal disease. Furthermore, those patients often present secondary hyperparathyroidism, partly because of a decrease of calcitriol synthesis on the kidney. Thus, one of the main therapeutic options is to treat those patients with calcitriol or analogs. However, this treatment presents unwanted side effects, such as increases in vascular calcification.. We tested the effect on vascular smooth muscle cell (VSMC) calcification of calcitriol and one of its analogs, paricalcitol, in vitro and in vivo in animals with endstage renal disease.. Calcitriol increased calcification of VSMCs cultured in calcification media. This effect was not present when cells were incubated with paricalcitol. Furthermore, only cells incubated with calcitriol showed an increased RANKL/osteoprotegerin (OPG) expression. Animals with renal failure treated with hypercalcemic doses of calcitriol and paricalcitol showed an increase in systolic blood pressure. However, diastolic blood pressure only raised significantly in those animals treated with paricalcitol. This effect led to a significant increase in pulse pressure in animals treated with calcitriol. The increase in pulse pressure was likely caused by the extensive calcification observed in arteries of animals treated with calcitriol. This increase in calcification was not seen in arteries of animals treated with paricalcitol, despite having similar levels of serum calcium and phosphorus as animals treated with calcitriol. Furthermore, the decreases in serum PTH levels were similar in both treatments.. We conclude that paricalcitol has a different effect than calcitriol in VSMC calcification and that this could explain part of the differences observed in the clinical settings.

Topics: Animals; Aorta; Blood Pressure; Bone Density Conservation Agents; Calcinosis; Calcitriol; Calcium; Cells, Cultured; Ergocalciferols; Gene Expression; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nephrectomy; Osteoprotegerin; Parathyroid Hormone; Phosphorus; RANK Ligand; Rats; Rats, Sprague-Dawley; Vascular Diseases; Vitamin D

Osteoprotegerin (OPG), a soluble decoy receptor for receptor activator of nuclear factor kappaB ligand, is implicated in the pathogenesis of atherosclerosis. Patients with rheumatoid arthritis (RA) have inflammation and increased atherosclerosis. We examined the hypothesis that OPG concentrations are increased in patients with RA and are associated with coronary-artery atherosclerosis. Serum OPG concentrations were measured by ELISA and coronary-artery calcification by electron-beam computer tomography in 157 patients with RA and 87 control subjects. OPG concentrations were higher in patients with long-standing RA (n=67) [median (interquartile range)]: [1895 (1337-2847) pg/mL, and early RA (n=90): [1340 (1021-1652) pg/mL, than controls 1068 (692-1434) pg/mL; (p<0.001)]. In patients with RA, OPG concentrations were associated with erythrocyte sedimentation rate (p<0.001), homocysteine (p=0.001), disease duration (p=0.02), coronary calcium score (p=0.03), and cumulative dose of corticosteroids (p=0.04) after adjustment for age and sex. In patients with long-standing RA, OPG was associated with coronary-artery calcification independently of cardiovascular risk factors and disease activity [OR for every increase in 500 pg/mL of OPG=2.22 (1.43-3.34), p<0.001]. In conclusion, OPG concentrations are increased in patients with RA and are associated with inflammation. In patients with long-standing disease, OPG is independently associated with coronary-artery calcification.

Topics: Adult; Aged; Arthritis, Rheumatoid; Biomarkers; Calcinosis; Case-Control Studies; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Osteoprotegerin; Radiography; Time Factors

Enhanced osteoclastogenesis, increased bone resorption, and osteoporosis have been reported in osteoprotegerin-deficient (OPG (-/-)) mice. OPG (-/-) mice available in Japan usually do not show vascular calcification. We have found that arterial calcification can be quickly induced by a simple procedure in OPG (-/-) mice.. Male OPG (-/-), OPG (+/-), and OPG (+/+) mice were fed a high phosphate diet from 6 to 10 weeks after birth, and then 1alpha,25-dihydroxyvitamin D3 (calcitriol) was injected for 3 days. We found that severe calcification developed in the media of the aorta in OPG (-/-) mice. Under electron microscopy, calcium deposits were observed in the cytoplasm and extracellular matrix of vascular smooth muscle cells (VSMCs). Neither apoptosis of VSMCs nor infiltration of macrophages was observed. Alkaline phosphatase (ALP) activity of aortic tissue correlated with the calcified lesion area. Mouse aorta and bone extracts revealed an identical pattern by ALP electrophoresis.. Our results demonstrated that OPG had anticalcification activity in the aorta, probably through the downregulation of ALP activity. Because the time course of arterial calcification after the injection of calcitriol is accurate and reproducible, this mouse model will be useful for further investigation of vascular calcification.

Topics: Alkaline Phosphatase; Animals; Aorta; Calcinosis; Calcitriol; Calcium; Cardiovascular Diseases; Disease Models, Animal; Down-Regulation; Male; Mice; Mice, Knockout; Osteoprotegerin; Vitamins

No mouse model is currently available where the induction of type 2 diabetes on an atherosclerotic background could be achieved without significant concomitant changes in plasma lipid levels. We crossbred 2 genetically modified mouse strains to achieve a model expressing both atherosclerosis and characteristics of type 2 diabetes. For atherosclerotic background we used low-density lipoprotein receptor-deficient mice synthetizing only apolipoprotein B100 (LDLR(-/-) ApoB(100/100)). Diabetic background was obtained from transgenic mice overexpressing insulin-like growth factor-II (IGF-II) in pancreatic beta cells. Thorough phenotypic characterization was performed in 6- and 15-month-old mice on both normal and high-fat Western diet. Results indicated that IGF-II transgenic LDLR(-/-)ApoB(100/100) mice demonstrated insulin resistance, hyperglycemia, and mild hyperinsulinemia compared with hypercholesterolemic LDLR(-/-)ApoB(100/100) controls. In addition, old IGF-II/LDLR(-/-)ApoB(100/100) mice displayed significantly increased lesion calcification, which was more related to insulin resistance than glucose levels, and significantly higher baseline expression in aorta of several genes related to calcification and inflammation. Lipid levels of IGF-II/LDLR(-/-)ApoB(100/100) mice did not differ from LDLR(-/-)ApoB(100/100) controls at any time. In conclusion, type 2 diabetic factors induce increased calcification and lesion progression without any lipid changes in a new mouse model of diabetic macroangiopathy.

Topics: Animals; Apolipoproteins B; Atherosclerosis; Blood Glucose; Calcinosis; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Hypercholesterolemia; Hyperglycemia; Insulin Resistance; Insulin-Like Growth Factor II; Lipids; Mice; Mice, Inbred C57BL; Mice, Transgenic; Osteoprotegerin; Receptors, LDL

Topics: Calcinosis; Coronary Disease; Estrogen Replacement Therapy; Estrogens; Female; Humans; Middle Aged; Osteoporosis, Postmenopausal; Osteoprotegerin

The bone-related protein osteoprotegerin (OPG) may be involved in the development of vascular calcifications, especially in diabetes, where it has been found in increased amounts in the arterial wall. Experimental studies suggest that members of the TGF-superfamily are involved in the transformation of human vascular smooth muscle cells (HVSMC) to osteoblast-like cells. In this study, we evaluated the effect of BMP-2, BMP-7 and transforming growth factor beta (TGF-beta1) on the secretion and mRNA expression of OPG and its ligands receptor activator of nuclear factor-kappabeta ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL) in HVSMC. All three growth factors decreased OPG protein production significantly; these results were paralleled by reduced OPG mRNA expression. TRAIL mRNA levels were also decreased. RANKL mRNA expression declined when treated with TGF-beta1 but were increased by both BMPs. Members of the TGF-superfamily, i.e. TGF-beta1, BMP-2 and BMP-7 exert effects on OPG and its ligands, indicating that these peptides may be involved in the development of vascular calcifications. The downregulation of OPG by these peptides does, however, not suggest that these factors are directly involved in OPG accumulation in diabetes.

Topics: Actins; Bone Morphogenetic Proteins; Calcinosis; Cells, Cultured; Diabetes Mellitus; Humans; Muscle, Smooth, Vascular; Osteoprotegerin; RANK Ligand; RNA, Messenger; TNF-Related Apoptosis-Inducing Ligand; Transforming Growth Factor beta

This study prospectively evaluated the relationship between cardiovascular risk factors, selected biomarkers (high-sensitivity C-reactive protein [hs-CRP], interleukin [IL]-6, and osteoprotegerin [OPG]), and the progression of coronary artery calcification (CAC) in type 2 diabetic subjects.. Coronary artery calcification is pathognomonic of coronary atherosclerosis. Osteoprotegerin is a signaling molecule involved in bone remodeling that has been implicated in the regulation of vascular calcification and atherogenesis.. Three hundred ninety-eight type 2 diabetic subjects without prior coronary disease or symptoms (age 52 +/- 8 years, 61% male, glycated hemoglobin [HbA(1)c] 8 +/- 1.5) were evaluated serially by CAC imaging (mean follow-up 2.5 +/- 0.4 years). Progression/regression of CAC was defined as a change > or =2.5 between the square root transformed values of baseline and follow-up volumetric CAC scores. Demographic data, risk factors, glycemic control, medication use, serum hs-CRP, IL-6, and plasma OPG levels were measured at baseline and follow-up.. Two hundred eleven patients (53%) had CAC at baseline. One hundred eighteen patients (29.6%) had CAC progression, whereas 3 patients (0.8%) had regression. Age, male gender, hypertension, baseline CAC, HbA(1)c >7, waist-hip ratio, IL-6, OPG, use of beta-blockers, calcium channel antagonists, angiotensin-converting enzyme (ACE) inhibitors, statins, and Framingham/UKPDS (United Kingdom Prospective Diabetes Study) risk scores were univariable predictors of CAC progression. In the multivariate model, baseline CAC (odds ratio [OR] for CAC >400 = 6.38, 95% confidence interval [CI] 2.63 to 15.5, p < 0.001), HbA(1)c >7 (OR 1.95, CI 1.08 to 3.52, p = 0.03), and statin use (OR 2.27, CI 1.38 to 3.73, p = 0.001) were independent predictors of CAC progression.. Baseline CAC severity and suboptimal glycemic control are strong risk factors for CAC progression in type 2 diabetic subjects.

Topics: Adult; Aged; Biomarkers; C-Reactive Protein; Calcinosis; Cohort Studies; Coronary Artery Disease; Diabetes Mellitus, Type 2; Disease Progression; Female; Glycated Hemoglobin; Humans; Interleukin-6; Male; Middle Aged; Osteoprotegerin; Risk Factors; Severity of Illness Index; Tomography, X-Ray Computed

In accordance with clinical findings, myringosclerosis develops after otitis media (OM) and paracentesis in an experimental setting. The pathogenesis of this phenomenon of calcification is poorly understood. As the calcification process and the sclerotic plaques of the drum mimics features of bone tissue, this study explores tympanic membrane calcium deposition in association with the expression of three bone modelling markers: osteopontin (OPN), osteoprotegerin (OPG) and osteonectin (ON). OPN is secreted by osteoblasts and is found at calcification sites, e.g. during pathological calcification in chronic OM. The cytokine OPG is an inhibitor of bone resorption and consequently bone remodelling. ON is a calcium binding glycoprotein necessary for the maintenance of bone mass and remodelling. It is found in bone matrix and synthesized by osteoblasts.. A rat model of acute otitis media (AOM) caused by non-typeable Haemophilus influenzae was used. Four days following middle ear inoculation, a myringotomy was performed in six animals. Another group of ten animals was inoculated only. The drum was dissected in two animals from each group on day 4, 7, 14 and 28 post-inoculation, and the expression of OPN, OPG and ON was determined by immunohistochemistry. von Kossa staining determined the deposition of calcium and immune staining for CD68 identified macrophages.. Calcium depositions were initially accumulated in the cytoplasm of macrophages and dispersed in the connective tissue layers of the pars flaccida and tensa. Late accumulation occurred in the lamina propria of pars tensa, more extensively in myringotomized ears. OPN expression was found early in inflammatory cells including especially macrophages and late in pars tensa fibrocytes. OPG expression was initially located to inflammatory cells and late to pars tensa fibrocytes and the inner basal membrane of pars flaccida. Some ears displayed a marked pars flaccida expression of ON in the connective tissue matrix on early days and at the inner basal membrane on later days. The latter cases were from myringotomized ears. Otherwise, no apparent differences of marker expression occurred between myringotomized and non-myringotomized animals.. We conclude that osteopontin, osteoprotegerin and osteonectin are expressed by different cell types in the tympanic membrane during calcification in association with AOM, with or without myringotomy. These molecules may accordingly play a role in the pathogenesis of myringosclerosis, in which macrophages and fibrocytes appear as potential major players.

Topics: Acute Disease; Animals; Bone Remodeling; Calcinosis; Calcium; Glycoproteins; Male; Osteonectin; Osteopontin; Osteoprotegerin; Otitis Media; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Sclerosis; Sialoglycoproteins; Tympanic Membrane

Topics: Animals; Calcinosis; Coronary Disease; Glycoproteins; Humans; Muscle, Smooth, Vascular; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Sodium-Phosphate Cotransporter Proteins

This study sought to prospectively evaluate the relationship between plasma osteoprotegerin (OPG), inflammatory biomarkers (high-sensitivity C-reactive protein [hs-CRP], interleukin-6 [IL-6], coronary artery calcification (CAC), and cardiovascular events in patients with type 2 diabetes.. Arterial calcification is a prominent feature of atherosclerosis and is associated with an increased risk of cardiovascular events. Osteoprotegerin is a cytokine that has recently been implicated in the regulation of vascular calcification.. A total of 510 type 2 diabetic patients (53 +/- 8 years; 61% male) free of symptoms of cardiovascular disease were evaluated by CAC imaging. Risk factors, hs-CRP, IL-6, and OPG levels were measured. Patients were followed up for cardiovascular events (cardiac death, myocardial infarction, acute coronary syndrome, late revascularization, and nonhemorrhagic stroke).. Significant CAC (>10 Agatston units) was seen in 236 patients (46.3%); OPG was significantly elevated in patients with increased CAC. In multivariable analyses, OPG retained a strong association with elevated CAC scores after adjustment for age, gender, and other risk factors (odds ratio = 2.84, 95% confidence interval 2.2 to 3.67; p < 0.01). Sixteen cardiovascular events occurred during a mean follow-up of 18 +/- 5 months. The waist-to-hip ratio, United Kingdom Prospective Diabetes Study (UKPDS) risk score, OPG level, and CAC score were significant predictors of time to cardiovascular events in a univariate Cox proportional hazards model. In the multivariate model, the CAC score was the only independent predictor of adverse events. Levels of hs-CRP and IL-6 were related to neither the extent of CAC nor short-term events.. A high proportion of asymptomatic diabetic patients have significant subclinical atherosclerosis. Of the biomarkers studied, only OPG predicted both subclinical disease and near-term cardiovascular events. Therefore, measurement of OPG merits further investigation as a simple test for identifying high-risk type 2 diabetic patients.

Topics: Biomarkers; C-Reactive Protein; Calcinosis; Cardiovascular Diseases; Coronary Artery Disease; Diabetes Mellitus, Type 2; Female; Glycoproteins; Humans; Interleukin-6; Male; Middle Aged; Osteoprotegerin; Prognosis; Proportional Hazards Models; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Risk Factors; Sensitivity and Specificity; Survival Rate

Osteoprotegerin (OPG) is a recently identified cytokine that acts as a decoy receptor for the receptor activator of the NF-kappaB ligand (RANKL). OPG has been shown to be an important inhibitor of osteoclastogenesis and arterial calcification in animal models. OPG has been proposed as a link molecule between osteoporosis and arterial calcification, but the relationship between the OPG gene and the cardiovascular system in human populations is unclear. Thus, the aim of this study was to investigate the relationship between OPG gene polymorphisms and aortic calcification or coronary artery disease in Koreans.. Genotyping of four polymorphisms, A163G, G209A, T245G and T950C, in the promoter region of the OPG gene was performed in 251 healthy Korean women (mean age 51.3 +/- 6.9 years) and in a second study population consisting of 100 patients who underwent coronary angiography (mean age 57.0 +/- 11.9 years), by allelic discrimination using the 5' nuclease polymerase chain reaction assay. Cardiovascular risk factors and serum OPG levels were measured and aortic calcification in thoracic and abdominal aorta was examined by simple radiological methods.. In the first study population, the prevalence of aortic calcification increased significantly as the subjects grew older. The frequencies of mutant alleles were significantly higher in the subjects with aortic calcification compared with those without aortic calcification in G209A and T950C polymorphisms, although these significances were lost after adjustment for age. No significant relationship was found between OPG gene polymorphisms and serum OPG levels or cardiovascular risk factors. In the second study group, there were no associations between OPG promoter genotypes and aortic calcification, serum OPG levels, or coronary artery disease.. We observed that the four polymorphisms in the promoter region of the OPG gene were not associated with aortic calcification or coronary artery disease in Koreans. Further studies are needed to clarify this relationship.

Topics: Adult; Aged; Analysis of Variance; Aorta; Calcinosis; Coronary Angiography; Coronary Disease; Female; Glycoproteins; Humans; Korea; Middle Aged; Osteoprotegerin; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Risk Factors

Osteoprotegerin (OPG), a member of the tumor necrosis factor (TNF) superfamily of proteins, plays an important role in bone remodeling and is expressed in both mouse and human atherosclerotic lesions. The current study was designed to assess whether OPG plays a role in the progression and calcification of advanced atherosclerotic lesions in apoE(-/-) mice.. Atherosclerotic lesion area and composition and aortic calcium content were examined in mice deficient in both OPG and apolipoprotein E (OPG(-/-).apoE(-/-) mice) at 20, 40, and 60 weeks of age. Littermate OPG(+/+).apoE(-/-) mice were used as controls. The average cross-sectional area of lesions in the innominate arteries was increased in OPG(-/-).apoE(-/-) mice at 40 and 60 weeks of age. The increase in lesion area was coupled with a reduced cellularity and an increase in connective tissue including laminated layers of elastin. Sixty-week-old OPG(-/-).apoE(-/-) mice also had an increase in the area of calcification of the lesions. There were no differences in markers of plaque stability. In vitro, OPG induced matrix metalloproteinase-9 (MMP-9) activity in macrophages and smooth muscle cells and acted as a survival factor for serum-deprived smooth muscle cells.. OPG inhibits advanced plaque progression by preventing an increase in lesion size and lesion calcification. OPG may act as a survival factor and may modulate MMP9 production in vascular cells.

Topics: Aging; Animals; Aorta; Atherosclerosis; Brachiocephalic Trunk; Calcinosis; Calcium; Carrier Proteins; Cell Survival; Disease Progression; Female; Glycoproteins; Male; Matrix Metalloproteinase 9; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocytes, Smooth Muscle; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Vascular calcifications are an important risk factor for cardiovascular mortality and morbidity in patients with chronic renal failure. Osteoprotegerin, a soluble decoy receptor for receptor activator NFkB ligand, has emerged as an independent predictive factor of atherosclerosis and vascular calcification in hemodialysis patients. Sparse data are available on the evolution of osteoprotegerin after renal transplantation. The aim of this study was to follow the evolution of serum osteoprotegerin levels and biochemical risk factors after renal transplantation. Forty patients were included. Blood samples for analysis were collected before and 3 months after renal transplantation. Besides the expected diminution in calcium-phosphate product, we have shown an early normalization of osteoprotegerin (10.05 +/- 4.77 pmol/L to 4.59 +/- 2.26 pmol/L). This study demonstrates that kidney transplantation improves this risk factor for vascular calcifications. However, these preliminary results should be confirmed and extended by the follow-up of vascular calcifications in the long term.

Topics: Adult; Biomarkers; Calcinosis; Creatinine; Female; Humans; Kidney Failure, Chronic; Kidney Function Tests; Kidney Transplantation; Male; Middle Aged; Osteoprotegerin; Treatment Outcome

Topics: Aorta, Abdominal; Aortic Diseases; Calcinosis; Glycoproteins; Humans; Osteopontin; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Severity of Illness Index; Sialoglycoproteins

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

OPG (osteoprotegerin) is an inhibitor of osteoclastogenesis and recent work suggests it has a role in atherosclerosis. Therefore we measured serum OPG levels in patients with coronary artery disease, compared the serum OPG levels among the different groups according to the number of stenotic vessels and determined whether there was any correlation with aortic calcification, LV (left ventricular) mass index and serum CRP (C-reactive protein) levels. Subjects (n=100; mean age, 57 years) who underwent coronary angiograms were enrolled. Blood pressure, body mass index, fasting blood glucose, lipid profiles and CRP levels were measured and the LV mass indices were calculated using ECGs. Serum OPG levels were measured by ELISA. The presence of calcification in the aortic notch was checked by a chest X-ray. The subjects were divided into four groups according to the number of stenotic vessels. The mean serum OPG levels increased significantly as the number of stenotic vessels increased, and the mean serum OPG levels were higher in the group with three-vessel disease compared with the groups with no- or one-vessel disease. The mean serum CRP level was significantly higher in the group with three-vessel disease compared with the groups with no-, one- and two-vessel disease. Age and LV mass index showed significant positive correlations with serum OPG levels, although significance was lost after an adjustment for age. Serum CRP levels were positively correlated with serum OPG levels even after an adjustment for age. There were no differences in serum OPG levels according to the presence of fasting hyperglycaemia or aortic calcification. In conclusion, serum OPG level was related to the severity of stenotic coronary arteries and serum CRP levels. LV mass indices showed no significant correlation with OPG levels. The precise mechanism for the role of OPG in atherosclerosis needs to be investigated further.

Topics: Aged; Aortography; Biomarkers; C-Reactive Protein; Calcinosis; Coronary Angiography; Coronary Disease; Disease Progression; Electrocardiography; Enzyme-Linked Immunosorbent Assay; Glycoproteins; Humans; Hypertrophy, Left Ventricular; Middle Aged; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Topics: Aorta, Abdominal; Aortic Diseases; Bone Density; Calcinosis; Cohort Studies; Female; Fractures, Bone; France; Glycoproteins; Humans; Middle Aged; Osteoporosis; Osteoprotegerin; Prevalence; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Risk Factors

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

The majority of patients with chronic kidney disease (CKD) have excessive vascular calcification; however, most studies demonstrate that a subset of CKD patients do not have, nor develop, vascular calcification despite similar exposure to the uremic environment. This suggests protective mechanisms, or naturally occurring inhibitors, of calcification may be important.. In order to determine the role of three inhibitors, fetuin-A, matrix gla protein (MGP), and osteoprotegerin (OPG) in the vascular calcification observed in patients with CKD-5, we (1) measured serum levels of these inhibitors and compared the levels to calcification assessed by computed tomography (CT); (2) examined arteries from CKD-5 patients by immunostaining for these inhibitors; and (3) examined the expression and effect of these inhibitors in cultured bovine vascular smooth muscle cells (BVSMCs) incubated in serum pooled from uremic patients compared to healthy controls.. There was a negative correlation of coronary artery calcification scores with serum fetuin-A levels (r=-0.30, P= 0.034) and a positive association with OPG levels (r= 0.29, P= 0.045). There was increasing immunostaining for both fetuin-A and MGP in arteries with increasing calcification graded semiquantitatively (P < 0.003). In vitro, fetuin-A added to mineralizing BVSMCs inhibited mineralization (P < 0.001). Compared to normal serum, BVSMCs incubated with uremic serum had a progressive increase in MGP expression with mineralization (P < 0.001) and increased expression of OPG in BVSMCs (P < 0.04).. These data demonstrate that fetuin-A, OPG, and MGP play an important role in the pathogenesis of uremic vascular calcification.

Topics: alpha-2-HS-Glycoprotein; Animals; Blood Proteins; Calcinosis; Calcium-Binding Proteins; Cattle; Cells, Cultured; Chronic Disease; Extracellular Matrix Proteins; Glycoproteins; Humans; Kidney Diseases; Matrix Gla Protein; Muscle, Smooth, Vascular; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

Takayasu arteritis (TA) is a chronic inflammatory disorder affecting the aorta and its branches. Vascular calcification has been described in 29-54% of cases of TA, although its aetiology remains unknown. Recently the osteoprotegerin/RANKL/RANK system has emerged as an important contributing factor to atherogenesis and osteogenesis. Our aim is to investigate the association between vascular calcification, bone mineral density (BMD) and the osteoprotegerin/RANK/RANKL system in TA.. Thirty pre-menopausal female TA patients and 30 age- and sex-matched controls were studied. BMD was measured by dual X-ray absorptiometry. Arterial calcification in TA patients was analysed by computed tomography in thoracic and abdominal sites. Serum levels of osteoprotegerin and soluble receptor activator of nuclear factor kappaB ligand (sRANKL) were quantified by enzyme-linked immunosorbent assay.. Patients with severe arterial calcification showed lower BMD values than controls in lumbar spine (0.965 +/- 0.055 vs 1.126 +/- 0.153 g/cm2, P = 0.009) and total body (0.993 +/- 0.065 vs 1.085 +/- 0.082 g/cm2, P = 0.019). In contrast, TA patients without calcification presented BMD values similar to controls (P > 0.05). Interestingly, lower serum levels of sRANKL (1.89 +/- 2.35 vs 2.80 +/- 2.23 pg/ml, P = 0.031) and a longer disease duration (12.20 +/- 6.61 vs 3.56 +/- 5.33 yr, P = 0.004) were observed in TA patients with severe calcification compared with patients without calcification.. Severe arterial calcification in TA is associated with low values of BMD and sRANKL, reinforcing the possible link between bone and vascular disease.

Topics: Adult; Aortic Diseases; Bone Density; Bone Diseases, Metabolic; Calcinosis; Carrier Proteins; Female; Glycoproteins; Humans; Lumbar Vertebrae; Membrane Glycoproteins; Osteoprotegerin; Premenopause; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Takayasu Arteritis

Vascular calcification, such as coronary and aortic calcification, is a significant feature of vascular pathology. Two distinct forms of vascular calcification are well recognized. One is medial calcification, which occurs between the cell layers of smooth muscle cells, and is related to aging, diabetes and chronic renal failure. The other is atherosclerotic calcification, which occurs in the intima during the development of atheromatous disease. It has been shown that statins inhibit the progression of calcification in the aortic valve and the coronary artery. We have found that statins inhibit calcification of human aortic smooth muscle cells, which is induced by incubating the cells in high-phosphate medium. We also found that this is mediated by inhibiting cellular apoptosis, an essential mechanism for calcification, not by inhibiting inorganic phosphate (Pi) uptake by sodium-dependent phosphate cotransporter (NPC). Besides apoptosis and Pi uptake, such proteins as osteoprotegerin (OPG), matrix Gla protein (MGP), Klotho, fetuin-A, and apoE have been shown to negatively affect vascular calcification. Many previous reports suggest that vascular calcification appears to be regulated by promoting factors, such as Pi, apoptosis, modified LDL, advanced glycation end products, oxidative stress, vitaminD3, glucocorticoid, cbfa-1, osteopontin, and inhibitory factors, such as OPG, MGP, Klotho, fetuin-A, PTH/PTHrP, pyrophosphate, statins, and bisphosphonates. The precise mechanism of vascular calcification is of interest.

Topics: Animals; Apoptosis; Atherosclerosis; Calcinosis; Cell Cycle Proteins; Glucuronidase; Glycoproteins; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Klotho Proteins; Membrane Proteins; Mice; Osteoprotegerin; Peptide Elongation Factor 1; Phosphates; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

Topics: Calcinosis; Carrier Proteins; Glycoproteins; Humans; Male; Membrane Glycoproteins; Middle Aged; Osteoprotegerin; Popliteal Artery; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

The present studies were carried out to evaluate the possible association between the presence of the fetuin-mineral complex in serum and vitamin D-induced artery calcification. The first experiment shows that there is a fetuin-mineral complex in the blood of rats in which extensive calcification of the artery media has been induced by treatment with vitamin D for 96 h, and that there is no detectable fetuin-mineral complex in the blood of rats in which artery calcification has been inhibited by concurrent treatment with ibandronate or osteoprotegerin. The second experiment shows that the timing of vitamin D-induced artery calcification correlates with the timing of the maximal increase in serum fetuin-mineral complex levels. Whereas both results indicate that serum levels of the fetuin-mineral complex are indeed associated with vitamin D-induced artery calcification, the biochemical basis for this association is presently unclear. One possibility is that high levels of the fetuin-mineral complex cause defects in the ability of fetuin to prevent the growth of the mineral component, which then seeds artery calcification. Another possibility is that the fetuin-mineral complex is the downstream product of a pathway that begins with the true causative agent, and that the serum level of the fetuin-mineral complex is a marker for the activity of this agent in blood. An unexpected finding of the present studies is that vitamin D-induced artery calcification is also correlated with a 65 to 75% reduction in serum fetuin, a reduction that appears to be caused by the clearance of the fetuin-mineral complex from serum.

Topics: alpha-Fetoproteins; Animals; Aorta, Abdominal; Aortic Diseases; Bone Resorption; Calcinosis; Diphosphonates; Glycoproteins; Ibandronic Acid; Male; Minerals; Osteoprotegerin; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vitamin D

Patients with vascular calcifications often have low bone mineral density (BMD), but it is still uncertain if osteoporosis and peripheral vascular disease (VD) are interrelated and linked by a common pathomechanism. Moreover, data on bone turnover in patients with advanced atherosclerosis are lacking. We measured BMD by dual-energy X-ray absorptiometry (DXA) and quantitative bone ultrasound (QUS), as well as the serum levels of osteocalcin (OC), bone-specific alkaline phosphatase (BAP), osteoprotegerin (OPG) and its ligand RANKL, and the urinary concentration of the C-terminal telopeptides of type I collagen (CrossLaps), in 36 patient (20 male and 16 female) with serious atherosclerotic involvement of the carotid and/or femoral artery to investigate the underlying mechanism of vascular and osseous disorders. Thirty age-matched and gender matched healthy individuals served as controls. After adjustment for age, BMD was significantly reduced at the lumbar spine in 23/36 (63%) patients (mean T score -1.71+/-1.42) and at the proximal femur in 34/36 (93%) patients (neck mean T score -2.5+/-0.88). Ten patients (27%) had abnormal QUS parameters. Gender and diabetes had no effect on the relationship between vascular calcification and bone density at any site measured. VD subjects had OC and BAP serum levels lower than controls (13.3+/-3.1 vs 27.7+/-3.3 ng/ml, P<0.01, and 8.4+/-2.3 vs 12.5+/-1.4 microg/l, P<0.01, respectively). Urinary CrossLaps excretion was not significantly different in patients with VD and in controls (257.9+/-138.9 vs 272.2+/-79.4 micro g/mmol Cr, respectively). Serum OPG and RANKL levels were similar in patients and in controls (3.5+/-1.07 vs 3.4+/-1.05 pmol/l, and 0.37+/-0.07 vs 0.36+/-0.06 pmol/l, respectively). We proved high occurrence of osteoporosis in VD, with evidence of age and gender independence. Negative bone remodelling balance would be a consequence of reduced bone formation, with no apparent increased activation of the OPG-RANKL system.

Topics: Absorptiometry, Photon; Aged; Arteriosclerosis; Biomarkers; Bone Density; Bone Remodeling; Calcinosis; Carotid Artery Diseases; Collagen; Female; Femoral Artery; Glycoproteins; Humans; Male; Middle Aged; Osteocalcin; Osteoporosis; Osteoprotegerin; Peptide Fragments; Peripheral Vascular Diseases; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Ultrasonography

- Recent studies have suggested that valvular calcification in calcific aortic stenosis (AS) may be actively regulated. "Receptor Activator of Nuclear factor kappaB Ligand" (RANKL) and osteoprotegerin (OPG) are members of a cytokine system involved in bone turnover and vascular calcification. Their role in calcific AS is not known.. - By immunohistochemistry using human aortic valves, RANKL was not expressed at relevant levels in controls but detectable in AS. OPG expression was marked in controls but significantly lower in AS. Areas containing focal calcification exhibited significantly less OPG-positive cells as compared to non-calcified regions. Stimulation with RANKL lead to a significant rise in matrix calcification, nodule formation, alkaline phosphatase activity, expression of the bone-type isoenzyme of alkaline phosphatase, and expression of osteocalcin in cultured human aortic valve myofibroblasts. Moreover, RANKL increased DNA binding of the essential osteoblast transcription factor cbfa-1.. - RANKL and OPG are differentially expressed in calcific AS. In cultured human aortic valve myofibroblasts, RANKL promotes matrix calcification and induces the expression of osteoblast-associated genes, indicating a transition towards an osteogenic phenotype. These results suggest that the RANKL-OPG pathway may regulate valvular calcification in calcific AS?

Topics: Aortic Valve; Aortic Valve Stenosis; Calcinosis; Carrier Proteins; DNA; Fibroblasts; Glycoproteins; Humans; Immunohistochemistry; Membrane Glycoproteins; Neoplasm Proteins; Osteogenesis; Osteoprotegerin; Protein Binding; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Sclerosis; Transcription Factors

Osteoprotegerin is a novel member of the tumor necrosis factor receptor superfamily and a soluble decoy receptor of the receptor activator of nuclear factor-kappaB ligand. Recent experimental research has implicated osteoprotegerin in atherogenesis, but epidemiological confirmation of this concept is sparse.. As part of the prospective, population-based Bruneck Study, severity, initiation, and progression of atherosclerosis were assessed in carotid arteries. Cases of incident cardiovascular disease and vascular mortality were carefully recorded over a 10-year period (1990 to 2000). Osteoprotegerin levels were measured in samples obtained at baseline and during follow-up. Serum osteoprotegerin showed a strong association with numerous vascular risk factors, including age, diabetes, markers of systemic inflammation, chronic infection, and smoking. In multivariate analyses, osteoprotegerin was significantly related to severity and 10-year progression of carotid atherosclerosis. Furthermore, a high level of osteoprotegerin was an independent risk factor for incident cardiovascular disease (adjusted relative risk for the top versus bottom tertile group for osteoprotegerin 2.2 [1.3 to 3.8]; P=0.001) and vascular mortality (adjusted relative risk for the top versus bottom tertile group for osteoprotegerin 3.1 [1.2 to 8.2]; P=0.010) but not for mortality due to nonvascular causes.. Osteoprotegerin is an independent risk factor for the progression of atherosclerosis and onset of cardiovascular disease.

Topics: Aged; Aged, 80 and over; Apoptosis; Biomarkers; Calcinosis; Cardiovascular Diseases; Carotid Artery Diseases; Cohort Studies; Comorbidity; Disease Progression; Female; Follow-Up Studies; Glycoproteins; Humans; Incidence; Italy; Male; Middle Aged; Odds Ratio; Osteoprotegerin; Prospective Studies; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Risk; Risk Factors; Sampling Studies; Ultrasonography; Vascular Diseases

Osteoprotegerin (OPG) is a glycoprotein that inhibits osteoclast differentiation and activity. OPG-deficient mice develop severe osteoporosis and medial arterial calcification. The expression of OPG is detected in early atherosclerotic lesions in non-uraemic patients. We examined whether serum OPG is associated with aortic calcification in haemodialysis patients.. Serum OPG was measured in 102 patients who were undergoing haemodialysis. The aortic calcification index (ACI) was assessed by computed tomography scans.. Serum OPG level, measured by enzyme-linked immunosorbent assay, was significantly greater in patients with higher ACI than in those with lower ACI. There was a direct relationship between ACI and serum OPG levels and a positive association between OPG and ACI (r = 0.483, P<0.0001). Multiple regression analyses indicated that serum OPG levels were independently associated with the severity of aortic calcification (P<0.0001).. These findings show that serum OPG levels are associated with the extent of vascular calcification, suggesting that OPG may be involved in the development of vascular calcification in haemodialysis patients.

Topics: Adult; Aged; Aged, 80 and over; Aortic Diseases; Calcinosis; Female; Glycoproteins; Humans; Male; Middle Aged; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Renal Dialysis; Severity of Illness Index

Vascular calcification may occur at different areas of the vessel wall, including the intima in atherosclerosis and the media in Mönckeberg's sclerosis. Medial calcification of arteries is common in patients with diabetes mellitus or chronic renal failure. Osteoprotegerin (OPG) and receptor activator of nuclear factor-kappaB ligand are essential modulators of bone homeostasis and may be involved in the process of vascular calcification. In this study we investigated arteries from patients with Mönckeberg's sclerosis and atherosclerosis. Apoptosis, which precedes vascular calcification in vitro, was assessed by an in situ ligation assay and was localized to the medial layer of arteries (Mönckeberg's sclerosis) and the neointima (atherosclerosis). Immunohistochemistry and in situ hybridization revealed OPG immunoreactivity and mRNA expression surrounding calcified areas in the medial layer (Mönckeberg's sclerosis), whereas OPG was mainly expressed adjacent to calcified neointimal lesions (atherosclerosis). Receptor activator of nuclear factor-kappaB ligand protein and mRNA were barely or not detectable. Of note, TNF-related apoptosis-inducing ligand, an inducer of apoptosis that is also blocked by OPG, displayed a similar spatial distribution as OPG. In summary, we demonstrate enhanced apoptosis adjacent to vascular calcification, and the concurrent expression of regulators of apoptosis and osteoclastic differentiation, TNF-related apoptosis-inducing ligand and OPG, suggesting their involvement in the pathogenesis of vascular calcification.

Topics: Aged; Aged, 80 and over; Apoptosis Regulatory Proteins; Arteriosclerosis; Calcinosis; Carrier Proteins; Case-Control Studies; Female; Glycoproteins; Humans; Immunohistochemistry; In Situ Hybridization; Male; Membrane Glycoproteins; Middle Aged; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; RNA, Messenger; Staining and Labeling; Tissue Distribution; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha; Vascular Diseases

We have previously shown that an endothelin receptor antagonist can regress medial arterial calcification in a rat model. The aim of this study was to characterize the phenotypic changes of vascular smooth muscle cells during calcification and mineral loss, in order to understand better the underlying mechanisms. Control Wistar rats were compared with rats treated only with warfarin/ vitamin K1 (15 mg/kg per day) for 8 weeks, or in combination with darusentan (30 mg/kg per day) for the final 4 weeks. Vascular smooth muscle cell, bone cell and macrophage phenotypes were evaluated by the local expression of alpha-actin, tartrate-resistant acid phosphatase and ED-1, respectively. Proteins involved in the modulation of bone resorption like osteopontin and osteoprotegerin were also evaluated by immunohistochemistry. The warfarin/vitamin K1 treatment increased medial arterial calcification ninefold (P < 0.05). At sites of calcification, there was a decrease in alpha-actin localization, and an appearance of osteopontin immunostaining. Histochemical and immunostaining for osteoclast and macrophage markers, as well as for osteoprotegerin, were negative. Although the extent of calcification foci was reduced by darusentan, protein localization in the calcified areas was not modified. Thus, the development of medial arterial calcification produces a phenotypic change in vascular smooth muscle cells that does not appear to be normalized in regions remaining calcified during mineral loss.

Topics: Animals; Aorta, Thoracic; Aortic Diseases; Calcinosis; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Macrophages; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Osteoclasts; Osteopontin; Osteoprotegerin; Phenotype; Phenylpropionates; Pyrimidines; Rats; Rats, Wistar; Receptors, Endothelin; Vitamin K 1; Warfarin

The aortic calcification index (ACI), estimated on abdominal computed tomographic scans, has been associated with the extent of arteriosclerosis in hemodialysis patients. However, the contribution of biochemical markers to the progression of vascular calcification in patients undergoing hemodialysis is not fully understood.. We examined the relationship between coronary risk factors; metabolic factors, including serum osteoprotegerin (OPG) concentration; and progression of vascular calcification in 26 dialysis patients.. Mean patient age was 52.6 +/- 8.7 (SD) years, and mean duration of dialysis therapy was 7.7 +/- 5.8 years. ACI was measured twice in each patient, and the mean interscan period was 4.9 +/- 0.3 years. Mean ACI changed from 22.2 +/- 24.2 to 33.9 +/- 28.8 overall, and mean change in ACI (DeltaACI) was 12.0 +/- 9.9. Patients were divided into 2 groups: slow progressors, with DeltaACI of 4.1 +/- 3.2 (n = 13), and rapid progressors, with DeltaACI of 19.8 +/- 7.9 (n = 13). Serum fasting glucose and CRP levels of rapid progressors were high, and their serum albumin and intact parathyroid hormone levels were low. Multiple regression analyses showed that serum OPG levels were independently associated with vascular calcification in the hemodialysis patients studied.. Rapid progression of vascular calcification was associated with dose of calcium carbonate prescribed and serum OPG concentration. The clinical significance of these observations remains to be determined.

Topics: Aortic Diseases; Arteriosclerosis; C-Reactive Protein; Calcinosis; Calcium; Calcium Carbonate; Disease Progression; Female; Glycoproteins; Humans; Kidney Failure, Chronic; Lipids; Longitudinal Studies; Male; Middle Aged; Osteoprotegerin; Parathyroid Hormone; Phosphorus; Prospective Studies; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Renal Dialysis; Risk Factors

Prostate cancer frequently metastasizes to bone. However, unlike many other tumors that produce osteolytic lesions, prostate cancer produces osteoblastic lesions through unknown mechanisms. In the current study, we explored the ability and mechanism of an osteotropic prostate cancer cell line (C4-2B) to induce mineralization.. C4-2B cells were grown in promineralization media. Mineral deposition was characterized using von Kossa staining, calcium retention, alizarin red staining, Raman spectroscopy, and electron microscopy. Expression of osteoblast-related proteins was determined by RT-PCR. The nuclear level of the bone-specific transcription factor Cbfa1 was determined using western analysis and the effect of inhibiting Cbfa1 function, using a "decoy" Cbfa1 response element oligo, on mineralization was determined.. The studies demonstrated that C4-2B cells, but not its nonosteotropic parent cell line LNCaP, has an osteoblastlike phenotype including production of alkaline phosphatase, osteocalcin, osteonectin, bone sialoprotein, osteoprotegerin (OPG), and OPG ligand. Most importantly, the C4-2B cells produced hydroxyapatite mineral in vitro. Furthermore, C4-2B cells expressed high nuclear levels of the bone-specific transcription factor Cbfa1, compared to LNCaP cells, which accounts for their ability to produce bone-specific proteins. Inhibition of Cbfa1, using decoy DNA Cbfa1 response elements, abrogated the ability of C4-2B to produce mineral. Finally, we determined that C4-2B cells express bone morphogenic protein-7, a known inducer of Cbfa1 expression.. These data demonstrate a novel mechanism through which prostate cancer cells may directly contribute to the osteoblastic component that characterize their skeletal metastatic lesions. Prostate 47:212-221, 2001.

Topics: Anthraquinones; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Bone Neoplasms; Calcinosis; Calcium; Cell Division; Core Binding Factor Alpha 1 Subunit; Durapatite; Gene Expression Regulation, Neoplastic; Glycoproteins; Humans; Male; Neoplasm Proteins; Osteoblasts; Osteoprotegerin; Prostatic Neoplasms; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Staining and Labeling; Transcription Factors; Transforming Growth Factor beta; Tumor Cells, Cultured

Topics: Animals; Bone Remodeling; Calcinosis; Female; Glycoproteins; Humans; Mice; Osteoporosis; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

The present experiments were carried out to test the hypothesis that arterial calcification is linked to bone resorption by determining whether the selective inhibition of bone resorption with osteoprotegerin will inhibit arterial calcification. In the first test, arterial calcification was induced by treating 22-day-old male rats with warfarin, a procedure that inhibits the gamma-carboxylation of matrix Gla protein and causes extensive calcification of the arterial media. Compared with rats treated for 1 week with warfarin alone, rats treated with warfarin plus osteoprotegerin at a dose of 1 mg/kg per day had dramatically reduced alizarin red staining for calcification in the aorta and in the carotid, hepatic, mesenteric, renal, and femoral arteries, and they had 90% lower levels of calcium and phosphate in the abdominal aorta (P<0.001) and in tracheal ring cartilage (P<0.01). More rapid arterial calcification was induced by treating 49-day-old male rats with toxic doses of vitamin D. Treatment for 96 hours with vitamin D caused widespread alizarin red staining for calcification in the aorta and the femoral, mesenteric, hepatic, renal, and carotid arteries, and osteoprotegerin completely prevented calcification in each of these arteries and reduced the levels of calcium and phosphate in the abdominal aorta to control levels (P<0.001). Treatment with vitamin D also caused extensive calcification in the lungs, trachea, kidneys, stomach, and small intestine, and treatment with osteoprotegerin reduced or prevented calcification in each of these sites. Measurement of serum levels of cross-linked N-teleopeptides showed that osteoprotegerin dramatically reduced bone resorption activity in each of these experiments (P<0.001). Therefore, we conclude that doses of osteoprotegerin that inhibit bone resorption are able to potently inhibit the calcification of arteries that is induced by warfarin treatment and by vitamin D treatment. These results support the hypothesis that arterial calcification is linked to bone resorption.

Topics: Animals; Arteries; Bone Resorption; Calcinosis; Collagen; Collagen Type I; Drug Antagonism; Glycoproteins; Lung; Male; Osteoprotegerin; Peptides; Rats; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Trachea; Vascular Diseases; Vitamin D; Warfarin

In the present study, we examined the expression of regulators of bone formation and osteoclastogenesis in human atherosclerosis because accumulating evidence suggests that atherosclerotic calcification shares features with bone calcification. The most striking finding of this study was the constitutive immunoreactivity of matrix Gla protein, osteocalcin, and bone sialoprotein in nondiseased aortas and the absence of bone morphogenetic protein (BMP)-2, BMP-4, osteopontin, and osteonectin in nondiseased aortas and early atherosclerotic lesions. When atherosclerotic plaques demonstrated calcification or bone formation, BMP-2, BMP-4, osteopontin, and osteonectin were upregulated. Interestingly, this upregulation was associated with a sustained immunoreactivity of matrix Gla protein, osteocalcin, and bone sialoprotein. The 2 modulators of osteoclastogenesis (osteoprotegerin [OPG] and its ligand, OPGL) were present in the nondiseased vessel wall and in early atherosclerotic lesions. In advanced calcified lesions, OPG was present in bone structures, whereas OPGL was only present in the extracellular matrix surrounding calcium deposits. The observed expression patterns suggest a tight regulation of the expression of bone matrix regulatory proteins during human atherogenesis. The expression pattern of both OPG and OPGL during atherogenesis might suggest a regulatory role of these proteins not only in osteoclastogenesis but also in atherosclerotic calcification.

Topics: Adult; Aged; Aorta, Abdominal; Arteriosclerosis; Calcinosis; Calcium-Binding Proteins; Carrier Proteins; Disease Progression; Extracellular Matrix Proteins; Female; Glycoproteins; Humans; Immunohistochemistry; In Situ Hybridization; Male; Matrix Gla Protein; Membrane Glycoproteins; Middle Aged; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; RNA, Messenger; Seminal Vesicle Secretory Proteins; Tunica Intima; Xanthomatosis

High systemic levels of osteoprotegerin (OPG) in OPG transgenic mice cause osteopetrosis with normal tooth eruption and bone elongation and inhibit the development and activity of endosteal, but not periosteal, osteoclasts. We demonstrate that both intravenous injection of recombinant OPG protein and transgenic overexpression of OPG in OPG(-/-) mice effectively rescue the osteoporotic bone phenotype observed in OPG-deficient mice. However, intravenous injection of recombinant OPG over a 4-wk period could not reverse the arterial calcification observed in OPG(-/-) mice. In contrast, transgenic OPG delivered from mid-gestation through adulthood does prevent the formation of arterial calcification in OPG(-/-) mice. Although OPG is normally expressed in arteries, OPG ligand (OPGL) and receptor activator of NF-kappaB (RANK) are not detected in the arterial walls of wild-type adult mice. Interestingly, OPGL and RANK transcripts are detected in the calcified arteries of OPG(-/-) mice. Furthermore, RANK transcript expression coincides with the presence of multinuclear osteoclast-like cells. These findings indicate that the OPG/OPGL/RANK signaling pathway may play an important role in both pathological and physiological calcification processes. Such findings may also explain the observed high clinical incidence of vascular calcification in the osteoporotic patient population.

Topics: Acid Phosphatase; Animals; Aorta; Blotting, Western; Bone Density; Calcinosis; Cathepsin K; Cathepsins; CHO Cells; Cricetinae; Femur; Glycoproteins; Humans; Immunohistochemistry; In Situ Hybridization; Isoenzymes; Mice; Mice, Knockout; Mice, Transgenic; NF-kappa B; Osteoclasts; Osteopetrosis; Osteoporosis; Osteoprotegerin; Radiography; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; Tartrate-Resistant Acid Phosphatase

Osteoprotegerin (OPG) is a secreted protein that inhibits osteoclast formation. In this study the physiological role of OPG is investigated by generating OPG-deficient mice. Adolescent and adult OPG-/- mice exhibit a decrease in total bone density characterized by severe trabecular and cortical bone porosity, marked thinning of the parietal bones of the skull, and a high incidence of fractures. These findings demonstrate that OPG is a critical regulator of postnatal bone mass. Unexpectedly, OPG-deficient mice also exhibit medial calcification of the aorta and renal arteries, suggesting that regulation of OPG, its signaling pathway, or its ligand(s) may play a role in the long observed association between osteoporosis and vascular calcification.

Topics: Animals; Arteries; Bone Density; Calcinosis; Disease Models, Animal; Female; Gene Targeting; Glycoproteins; In Situ Hybridization; Male; Mice; Mice, Knockout; Osteoporosis; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases

Calcification of extracellular matrix (ECM) can be either physiological or pathological. Physiological calcification (or mineralization) of ECM is restricted to bones, teeth and, to a lesser extent, growth plate cartilages. Pathological calcification appears often in the ECM of arteries where it is a frequent complication of atherosclerosis. However, calcification of the ECM of arteries is not restricted to atherosclerosis. Indeed, human diseases have been described that are characterized by calcification of the aortic media in the absence of any atherosclerotic lesions. The existence of these rare diseases, along with several mouse models recently generated and discussed below, indicates that the formation of atherosclerotic lesions and the calcification of the artery ECM are controlled by different genetic pathways. This emerging knowledge has implications for our understanding of ECM calcification beyond atherosclerosis.

Topics: Animals; Arteries; Arteriosclerosis; Calcinosis; Calcium-Binding Proteins; Extracellular Matrix; Extracellular Matrix Proteins; Glycoproteins; Humans; Matrix Gla Protein; Mice; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Vascular Diseases; Vitamin K