Serum Receptor Activator Of NF-kappaB Ligand Research Articles

Correlation of OPG/RANKL in patients with thalassemia major at the center of Haemoglobinopathy Lushnje, Albania

Osteoporosis is an important cause of morbidity in hemoglobinopathy patients. It is characterized by low bone mass and disruption of bone architecture, resulting in reduced bone strength and increased risk of fractures. Osteoprotegerin (OPG) and receptor activator of NF-kappa-B ligand (RANKL) have recently been implicated in the pathogenesis of various types of osteoporosis. Our study aimed to determine the correlation between OPG/RANKL and patients affected by thalassemia major at the Center of Hemoglobinopathy in Lushnje. Methods: We measured serum OPG and RANKL levels in 70 patients with Thalassemia major and 67 healthy controls, determining correlations with BMD. Results: Serum OPG levels were significantly lower in thalassemic patients compared to the control group. Serum RANKL levels were higher in β-thalassemia patients compared to controls. 31.1% of our patients with Thalassemia major had osteoporosis and 21.6 % had osteopenia. We found a correlation between OPG-BMD (r=-0.768, p=0.000, and RANKL-BMD (r=0.468; p=0.000). Conclusion: OPG and RANKL in Thalassemia major patients should be considered as the main factors responsible for osteoclast activation.

Serum levels of M-CSF, RANKL and OPG in rats fed with Kashin-Beck disease-affected diet.

ObjectiveThere were no studies on the macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) in the pathogenesis of Kashin-Beck disease (KBD). The objective of the present study was to investigate the serum M-CSF, RANKL and OPG in rats fed with KBD-affected diet.MethodsNinety Wistar rats were divided into five groups. The rats received standard commercial feed with or without T-2 toxin additive, low protein feed with or without or T-2 toxin additive and the KBD-affected feed. The serum bioactivity of M-CSF, RANKL and OPG was tested by enzyme-linked immunosorbent assay.ResultsThe serum levels of M-CSF in E group rats were higher than those in the other groups in the five groups (P < 0.01). The serum levels of RANKL and OPG in E group rats were highest in the five groups and have significant difference compared to the other groups (P < 0.05).ConclusionsThe molecule of M-CSF, RANKL and OPG may be involved in the regulation of epiphyseal plate injury and repair in KBD, and its participation in the pathogenesis of KBD should be studied in the future.

AB0390 Serum RANKL Activity is Suppressed by TNF Alpha Inhibition but not with MTX Alone

BackgroundBone is, together with cartilage a central target of rheumatoid arthritis (RA). Chronic synovitis attacks the juxtaarticular bone, where it causes bone erosions. Formation of bone erosions is a consequence...

AB0557 Effects of tocilizumab on bone homeostasis and DICKKOPF-1 in rheumatoid arthritis

BackgroundTocilizumab (TCZ) is a humanized monoclonal anti-IL-6 receptor antibody. TCZ has demonstrated efficacy in moderate to severe active rheumatoid arthritis (RA) with inadequate clinical response to disease-modifying anti-rheumatic drugs (DMARD)...

The Clinical Significance of OPG/sRANKL Ratio in Thalassemia Patients Suffering from Osteopenia or Osteoporosis in Egyptian Patients

Osteopenia and osteoporosis are considered major health problems in patients suffering from thalassemia due to increased life expectancy of those patients. Osteoprotegerin (OPG) and receptor activator of NF-kappa-B ligand (RANKL) have been recently implicated in the pathogenesis of various types of osteoporosis. The aim of this study is to evaluate the role of serum OPG/RANKL ratio in patients suffering from thalassemia complicated with osteoporosis. Serum OPG and RANKL were measured in thalassemia patients and 20 healthy control subjects, using ELISA methods. Stastistically, the results demonstrate lower OPG and OPG/RANKL ratio in patients suffering from thalassemia with documented osteopenia or osteoporosis in comparison with control group and patients suffering from thalassemia without osteopenia or osteoporosis. OPG/RANKL ratio could become a promising rapid and cheap screening marker for osteopenia or osteoporosis in patients suffering from thalassemia. Furthermore, OPG may become a therapeutic option in treatment of osteoporosis of various etiologies including thalassemia.

RANKL inhibition by osteoprotegerin prevents bone loss without affecting local or systemic inflammation parameters in two rat arthritis models: comparison with anti-TNFα or anti-IL-1 therapies

IntroductionRat adjuvant-induced arthritis (AIA) and collagen-induced arthritis (CIA) feature bone loss and systemic increases in TNFα, IL-1β, and receptor activator of NF-κB ligand (RANKL). Anti-IL-1 or anti-TNFα therapies consistently reduce inflammation in these models, but systemic bone loss often persists. RANKL inhibition consistently prevents bone loss in both models without reducing joint inflammation. Effects of these therapies on systemic markers of bone turnover and inflammation have not been directly compared.MethodsLewis rats with established AIA or CIA were treated for 10 days (from day 4 post onset) with either PBS (Veh), TNFα inhibitor (pegsunercept), IL-1 inhibitor (anakinra), or RANKL inhibitor (osteoprotegerin (OPG)-Fc). Local inflammation was evaluated by monitoring hind paw swelling. Bone mineral density (BMD) of paws and lumbar vertebrae was assessed by dual X-ray absorptiometry. Markers and mediators of bone resorption (RANKL, tartrate-resistant acid phosphatase 5b (TRACP 5B)) and inflammation (prostaglandin E2 (PGE2), acute-phase protein alpha-1-acid glycoprotein (α1AGP), multiple cytokines) were measured in serum (day 14 post onset).ResultsArthritis progression significantly increased paw swelling and ankle and vertebral BMD loss. Anti-TNFα reduced paw swelling in both models, and reduced ankle BMD loss in AIA rats. Anti-IL-1 decreased paw swelling in CIA rats, and reduced ankle BMD loss in both models. Anti-TNFα and anti-IL-1 failed to prevent vertebral BMD loss in either model. OPG-Fc reduced BMD loss in ankles and vertebrae in both models, but had no effect on paw swelling. Serum RANKL was elevated in AIA-Veh and CIA-Veh rats. While antiTNFα and anti-IL-1 partially normalized serum RANKL without any changes in serum TRACP 5B, OPG-Fc treatment reduced serum TRACP 5B by over 90% in both CIA and AIA rats. CIA-Veh and AIA-Veh rats had increased serum α1AGP, IL-1β, IL-8 and chemokine (C-C motif) ligand 2 (CCL2), and AIA-Veh rats also had significantly greater serum PGE2, TNFα and IL-17. Anti-TNFα reduced systemic α1AGP, CCL2 and PGE2 in AIA rats, while anti-IL-1 decreased systemic α1AGP, IL-8 and PGE2. In contrast, RANKL inhibition by OPG-Fc did not lessen systemic cytokine levels in either model.ConclusionsAnti-TNFα or anti-IL-1 therapy inhibited parameters of local and systemic inflammation, and partially reduced local but not systemic bone loss in AIA and CIA rats. RANKL inhibition prevented local and systemic bone loss without significantly inhibiting local or systemic inflammatory parameters.

Replacement of Bone Marrow by Bone in Rat Femurs: The Bone Bioreactor

During development and repair of bone, two distinct yet complementary mechanisms, intramembranous and endochondral, mediate new bone formation via osteoblasts. Because mechanical bone marrow ablation leads to the rapid and transient formation of new bone in the marrow cavity, we postulated that parathyroid hormone (PTH), which is a bone anabolic hormone, enhances the formation of new bone that forms after marrow ablation. We subjected the left femur of rats to mechanical marrow ablation, or sham operation, and injected the animals daily with PTH or vehicle for 1, 2, or 3 weeks in a first experiment, then with PTH, parathyroid hormone-related peptide (PTHrP), or vehicle for 3 weeks in a second experiment. We subjected both femurs from each rat to soft X-ray, peripheral quantitative computed tomography, computed tomography on a microscale, and histological analysis, and determined the concentration of serum osteocalcin. In addition, in the second experiment, we determined the serum concentration of calcium, tartrate-resistant acid phosphatase (TRAP), and receptor activator of NF-kappaB ligand (RANKL) at 3 weeks, and subjected femurs to biomechanical testing. Following treatment with PTH or PTHrP for 3 weeks, bone filled the marrow cavity of the shafts whose marrow had been ablated. PTH increased trabecular density in the right femur, but failed to induce bone formation in the medullary region of the right unoperated femoral shafts. The newly formed bone endowed left femoral shafts with improved biomechanical properties when compared to those of right femurs and left femurs from control, sham-operated, and vehicle-treated rats. PTHrP, like PTH, increased serum osteocalcin, but neither increased serum calcium, TRAP, or RANKL at 3 weeks. Our results reveal that the newly formed bone that follows marrow ablation is responsive to PTH, expand the role of PTH in bone, and might open new avenues of investigations to the field of regenerative medicine and tissue engineering. Local bone marrow removal in conjunction with pharmacologic intervention with an anabolic agent might provide a technique for rapid preferential site-directed bone growth in areas of high bone loss.

Role of OPG in regulation of bone remodeling

Osteoprotegerine (OPG) acts as a decoy receptor for receptor activator of NF-kappaB (RANK) ligand (RANKL) to compete against RANK. OPG-deficient mice exhibit severe osteoporosis with accelerated bone remodeling. In human, several homozygous mutations in OPG gene were found in patients with juvenile Paget's disease. Missense mutations in cysteine residues in ligand binding domain, as well as complete deletion mutation, were associated with a severe phenotype characterized by enhanced bone remodeling and deformity. Serum RANKL level was elevated in OPG-deficient mice and a patient with complete deletion mutation. These results suggest that OPG represses the production of soluble form of RANKL. The elevated RANKL level in serum of OPG-deficient mice was not reduced by treatment with anti-resorbing agent, risedronate, but was upregulated by 1,25 (OH) (2)D(3) administration or ovariectomy.

Circulating osteoprotegerin and receptor activator of NF‐κB ligand system are associated with bone metabolism in middle‐aged males

Osteoporosis is a growing health problem in males as well as in females. Sex hormones and insulin-like growth factor-I (IGF-I) have been shown to be the major determinants in male bone metabolism. Osteoprotegerin (OPG) is a recently identified cytokine that acts as a decoy receptor for the receptor activator of NF-kappaB ligand (RANKL). OPG and RANKL have been shown to be important regulators of osteoclastogenesis. However, the relationship between the OPG-RANKL system and male bone status in human populations are unclear. Thus, the aim of this study was to investigate the relationship between the OPG-RANKL system and bone mineral metabolism in males. Serum concentrations of OPG, RANKL, oestradiol, total testosterone and IGF-I and bone mineral density (BMD) were measured in 80 Korean males aged 42-70 (mean age, 54.5 year). Enzyme-linked immunosorbent assays were used to determine the serum concentrations of OPG and RANKL. Serum concentrations of oestradiol, total testosterone, IGF-I and bone turnover markers were determined using standard methods. BMD at the lumbar spine and femoral neck were measured by dual energy X-ray absorptiometry. We observed a significant negative correlation between the serum OPG levels and lumbar spine BMD (r =-0.259, P < 0.05) in Spearman correlation analysis. Serum OPG levels and RANKL/OPG ratios were found to be significantly correlated to the serum osteocalcin levels (r =- 0.254, P < 0.05; r = 0.264, P < 0.05) in Spearman correlation analysis. Serum OPG levels were found to be negatively correlated with serum oestradiol levels (r =-0.319, P < 0.01) in Spearman correlation analysis. In addition, a significant positive correlation was found between serum RANKL/OPG ratios and oestradiol levels (r = 0.374, P < 0.001) in Spearman correlation analysis. In contrast, Serum total testosterone and IGF-I levels were not correlated with serum OPG levels or RANKL to OPG ratios in Spearman correlation analysis. In a multiple regression analysis, age, body mass index (BMI), and serum OPG levels were identified as a significant predictor for lumbar spine BMD, and age, BMI, serum OPG and RANKL levels for femoral neck BMD. In another multiple regression analysis, only serum oestradiol level was identified as a significant predictor for serum OPG or RANKL levels. In contrast, Serum total testosterone and IGF-I levels were not correlated with serum OPG or RANKL levels in multiple regression analysis. Our data show that the circulating OPG-RANKL system is associated with bone metabolism in the male populations. Also, our data suggest that OPG and RANKL may be mediators of the effects of oestradiol in male bone metabolism.