Bone mineral density in egyptian children with juvenile idiopathic arthritis: possible correlation to serum RANKL / osteoprotegerin (OPG) ratio and OPG gene polymorphisms.

BACKGROUND: Children with juvenile idiopathic arthritis (JIA) are at higher risk of decreased bone mineral density (BMD) compared with healthy children due to genetic, disease and medication-related causes. This study aims to investigate the possible effects of osteoprotegerin (OPG) gene polymorphisms and serum levels of osteoprotegerin (OPG) and receptor activator of nuclear factor κB-ligand (RANKL) and RANKL/OPG ratio on BMD in children with JIA. METHODS: OPG gene rs2073617, rs3134069, serum RANKL, OPG and RANKL/OPG ratio were evaluated in 60 JIA children and 100 matched healthy controls. BMD was evaluated by lumbar dual energy X-ray absorptiometry (DEXA) according to which patients were classified in 2 groups (DEXA z-score above and below - 2). Composite disease activity was measured using the Juvenile Arthritis Disease Activity Score (JADAS) 27-joints. Articular damage was scored using the juvenile arthritis damage index (JADI). RESULTS: Patients aged 12.05 ± 3.2 years, included 38 females and 31% had BMD z-score below-2. Systemic-onset JIA was the most frequent phenotype (38%). Genotypes and alleles frequencies of the 2 studied polymorphisms did not differ between patients and controls (p > 0.05 for all) while serum RANKL and RANKL/OPG ratio were significantly higher in patients compared to controls (p = < 0.001 and 0.03 respectively). Patients with BMD < -2 had significantly greater frequencies of rs2073617 TT genotype and T allele (p < 0.001), higher serum RANKL, RANKL/OPG ratio (p = 0.01, 0.002), female predominance (p = 0.02), higher articular and extra-articular damage index (p = 0.008,0.009) and more frequent steroid usage (p = 0.02) compared to patients with BMD z-score >-2. Multivariate analysis showed rs2073617 TT genotype, RANKL/OPG ratio, long disease duration (above 36 months) and use of steroid to be associated with decreased BMD (p = 0.03,0.04,0.01,0.01 respectively) in JIA children. CONCLUSIONS: Egyptian children with JIA have decreased BMD. rs2073617 TT genotype and T allele, RANKL/OPG ratio are possible determinants of reduced BMD in JIA. Our results underline the importance of frequent monitoring of BMD in JIA children and trying to control disease activity to preserve long term bone health.

Investigating the Relationship between the Levels of IL18, RANKL Gene Expression, MicroRNA-146a and Inflammatory Factors with the Severity of COVID-19.

COVID-19 can induce lung inflammation, and inflammatory factors play an essential role in its pathogenesis. This inflammation can be controlled to a great extent by microRNAs(miRs). This study evaluated miR-146a-5p expression levels in the serum of patients with COVID-19 and their association with the expression of interleukin (IL)-18 and receptor activator of nuclear factor kappa-Β ligand (RANKL) genes, and lung damage. patients with COVID-19 were divided into two groups: mild and severe phases. The severe phase is defined as having a positive polymerase chain reaction (PCR) for SARS-CoV2, and acute pulmonary symptoms. The subjects' demographic, clinical, and paraclinical characteristics were collected according to a pre-prepared checklist. Total RNA was isolated from all samples using the Trizol kit to assess gene expression. The extracted product was then evaluated for the expression of miR-146a and the target genes (i.e., IL-18 and RANKL) using real-time PCR. The miR-146a gene's mean expression in mild and severe patients was 0.73 and 1.89, respectively, and this difference was statistically significant between the two groups. Also, the mean Expression of the IL-18 gene, 1.37±0.38 in the mild and 2.83±0.58 in the severe groups of the disease, demonstrated a significant difference between the two groups. In contrast, the expression levels of the RANKL gene did not show a significant difference between the two groups. Therefore, it may be hypothesized that altered levels of miR-146a may contribute to the severe COVID-19 that is more commonly observed in smokers, but further research is required.

Decreased level of soluble receptor activator of nuclear factor-κß ligand (sRANKL) in overweight and obese children.

Introduction: Childhood obesity contributes to the development of cardiovascular diseases. The molecular pathway - receptor activator of nuclear factor-κß ligand (RANKL), its receptor RANK and osteoprotegerin (OPG) - takes part not only in bone metabolism but is also involved in the atherosclerosis process. RANKL stimulates osteogenic differentiation and calcification of vascular smooth cells. The associations between the OPG-sRANKL system and various cardiovascular risk factors were displayed. We aimed to evaluate the relationships between serum sRANKL (soluble RANKL) levels and the OPG/sRANKL ratio with cardiometabolic risk factors in overweight and obese children. Material and methods: The study included 70 children with overweight and obesity (mean age 13.0 ± 2.8) and 35 age-matched normal weight, healthy peers as a control group. In all patients, anthropometric measurements and laboratory tests were performed. Additionally, an oral glucose tolerance test (OGTT) was made only in overweight and obese children. Atherogenic and insulin resistance indices were calculated. Results: Overweight and obese children had lower sRANKL levels compared to the control group (median 276.95 vs 325.90, p=0.011), and consequently a higher OPG/sRANKL ratio (0.02 vs 0.01, p = 0.013). The studied children in the lowest quartile of sRANKL levels had higher body weight, Body Mass Index, waist circumference and increased glucose and insulin levels 60 minutes after OGTT and higher uric acid values compared to children in the highest quartile. In multivariable linear regression analysis sRANKL negatively correlated only with uric acid (ß = - 0.508, p = 0.041). No association was found for the OPG/sRANKL ratio. Conclusion: Excess fat mass seems to alter the OPG/RANKL ratio mainly by reducing serum sRANKL levels. The correlation between sRANKL and uric acid may suggest a contribution of the OPG-sRANKL system in the cardiometabolic process, but that observation should be confirmed in future studies.

Associations of Bone Mineral Density with RANKL and Osteoprotegerin in Arab Postmenopausal Women: A Cross-Sectional Study.

Background and objective: There is limited information as to the association of several key bone markers with bone mineral density (BMD) in understudied ethnic groups. This study investigated the relationship between circulating levels of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-Β ligand (RANKL) with BMD in Arab postmenopausal women. Materials and methods: In this cross-sectional study, a total of 617 Saudi postmenopausal women from the Osteoporosis Registry of the Chair for Biomarkers of Chronic Diseases were included. Anthropometric data, BMD, and biochemical data were retrieved from the registry. Participants were stratified into three groups based on T-score; n = 169 with osteoporosis, n = 282 with osteopenia, and n = 166 normal. Analysis of bone markers including RANKL, OPG, osteocalcin, and N-terminal telopeptide (NTx) was completed using commercially available bioassays. Results: The results suggested that OPG was significantly and positively correlated with age in the osteoporosis group (r = 0.29, p < 0.05), while it was inversely correlated with BMD femoral neck left (r = −0.56, p < 0.001) and BMD femoral neck right (r = −0.37, p < 0.05) in the same group. Moreover, RANKL showed a significant inverse correlation with NTx in the osteopenia group (r = −0.37, p < 0.05). Furthermore, the RANKL/OPG ratio had a positive and significant correlation with BMI (r = 0.34, p < 0.05), BMD femoral neck left (r = 0.36, p < 0.05) and BMD femoral neck right (r = 0.35, p < 0.05) in the osteopenia group. By contrast, it showed a significant inverse correlation with waist to hip ratio in the osteoporosis group (r = −0.38, p < 0.05). Multiple regression analysis showed that OPG contributes to BMD variations in the osteopenia group (p = 0.03). Conclusions: In conclusion, changes in circulating levels of RANKL and OPG might be a protective mechanism contrary to the increased bone loss in postmenopausal women.

The Short-Term Effect of Prunes in Improving Bone in Men.

Osteoporosis is a major health concern in aging populations, where 54% of the U.S. population aged 50 and older have low bone mineral density (BMD). Increases in inflammation and oxidative stress play a major role in the development of osteoporosis. Men are at a greater risk of mortality due to osteoporosis-related fractures. Our earlier findings in rodent male and female models of osteoporosis, as well as postmenopausal women strongly suggest the efficacy of prunes (dried plum) in reducing inflammation and preventing/reversing bone loss. The objective of this study was to examine the effects of two doses of prunes, daily, on biomarkers of inflammation and bone metabolism in men with some degree of bone loss (BMD; t-score between -0.1 and -2.5 SD), for three months. Thirty-five men between the ages of 55 and 80 years were randomized into one of three groups: 100 g prunes, 50 g prunes, or control. Consumption of 100 g prunes led to a significant decrease in serum osteocalcin (p < 0.001). Consumption of 50 g prunes led to significant decreases in serum osteoprotegerin (OPG) (p = 0.003) and serum osteocalcin (p = 0.040), and an increase in the OPG:RANKL ratio (p = 0.041). Regular consumption of either 100 g or 50 g prunes for three months may positively affect bone turnover.

Changes in Serum Dickkopf-1, RANK Ligand, Osteoprotegerin, and Bone Mineral Density after Allogeneic Hematopoietic Stem Cell Transplantation Treatment.

BACKGROUND: Dickkopf-1 (DKK1) regulates bone formation by inhibiting canonical Wnt/ß-catenin pathway signaling, and indirectly enhances osteoclastic activity by altering the expression ratio of receptor activator of nuclear factor-κB ligand (RANKL) relative to osteoprotegerin (OPG). However, it is difficult to explain continued bone loss after allogeneic stem cell transplantation (allo-SCT) in terms of changes in only RANKL and OPG. Few studies have evaluated changes in DKK1 after allo-SCT. METHODS: We prospectively enrolled 36 patients with hematologic malignancies who were scheduled for allo-SCT treatment. Serum DKK1, OPG, and RANKL levels were measured before (baseline), and at 1, 4, 12, 24, and 48 weeks after allo-SCT treatment. Bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry before (baseline) and 24 and 48 weeks after allo-SCT treatment. RESULTS: After allo-SCT treatment, the DKK1 level decreased rapidly, returned to baseline during the first 4 weeks, and remained elevated for 48 weeks (P<0.0001 for changes observed over time). The serum RANKL/OPG ratio peaked at 4 weeks and then declined (P<0.001 for changes observed over time). BMD decreased relative to the baseline at all timepoints during the study period, and the lumbar spine in female patients had the largest decline (-11.3%±1.6% relative to the baseline at 48 weeks, P<0.05). CONCLUSION: Serum DKK1 levels rapidly decreased at 1 week and then continued to increase for 48 weeks; bone mass decreased for 48 weeks following engraftment in patients treated with allo-SCT, suggesting that DKK1-mediated inhibition of osteoblast differentiation plays a role in bone loss in patients undergoing allo-SCT.

Assessment of Serum sRANKL, sRANKL/OPG Ratio, and Other Bone Turnover Markers with the Estimated 10-Year Risk of Major and Hip Osteoporotic Fractures in Rheumatoid Arthritis: A Cross-Sectional Study.

BACKGROUND: Fracture risk assessment tool (FRAX) index was developed for estimating of the 10-year risk of major or hip osteoporotic fracture. To date, there is insufficient information regarding the correlation between FRAX and serum bone turnover markers (BTMs), such as soluble ligand of receptor activator of nuclear factor-κB (sRANKL), osteoprotegerin (OPG), and other molecules related with secondary osteoporosis in rheumatoid arthritis (RA). Therefore, this study is aimed at assessing the correlation between the FRAX and serum levels of sRANKL, OPG, sRANKL/OPG ratio, Dickkopf-1 (DKK-1), and sclerostin (SOST) in RA. METHODS: Cross-sectional study included 156 postmenopausal women with RA. Bone mineral density (BMD) was measured at lumbar spine (L1-L4) and total hip using dual-energy X-ray absorptiometry (DXA). RA patients were divided into (A) RA + osteoporosis and (B) RA without osteoporosis. FRAX scores were calculated including the total hip BMD. Serum sRANKL, OPG, DKK-1, and SOST levels were measured by ELISA. Pearson tests were used for assessing the correlation between serum levels of these molecules and FRAX scores in RA. RESULTS: The RA + osteoporosis group had elevated sRANKL levels (p = 0.005), higher sRANKL/OPG ratio (p = 0.017), decreased DKK-1 (p = 0.028), and lower SOST levels (p < 0.001). Low total hip BMD correlated with high sRANKL (p = 0.001) and sRANKL/OPG ratio (p = 0.005). Total hip and lumbar spine BMD correlated with DKK-1 (p = 0.009 and p = 0.05, respectively) and SOST levels (p < 0.001 and p < 0.001, respectively). Higher sRANKL levels and sRANKL/OPG ratio correlated with estimated 10-year risk of a major osteoporotic fractures (p = 0.003 and p = 0.003, respectively) and hip fracture (p = 0.002 and p = 0.006, respectively). High serum SOST levels were associated with a low estimated 10-year risk of a major osteoporotic fracture (p = 0.003) and hip fracture (p = 0.009). CONCLUSION: High sRANKL levels and sRANKL/OPG ratio can be useful to detect a subgroup of RA patients who has an increased 10-year risk of major and hip osteoporotic fractures.

Physical activity and Mediterranean diet as potential modulators of osteoprotegerin and soluble RANKL in gBRCA1/2 mutation carriers: results of the lifestyle intervention pilot study LIBRE-1.

PURPOSE: Emerging evidence suggests that the progesterone-mediated receptor activator of nuclear factor κB (RANK)/soluble RANK ligand (sRANKL)/osteoprotegerin (OPG) pathway plays an important role in mammary carcinogenesis and is hyperactivated in germline (g)BRCA1/2 mutation carriers. We analyzed the effects of a 3-month intensive lifestyle intervention within the LIBRE-1 study on the serum levels of OPG and sRANKL and hypothesized that the intervention program provides a beneficial impact on the biomarkers by increasing OPG and reducing sRANKL serum concentrations. METHODS: Serum levels of OPG and sRANKL of 49 gBRCA1/2 mutation carriers were quantified using enzyme-linked immunosorbent assays. We used previously collected blood samples from participants of the prospective LIBRE-1 study, who were randomized into an intervention group (IG), increasing physical activity and adherence to the Mediterranean diet (MedD) through supervised sessions from study entry to the first study visit after 3 months and a usual-care control group (CG). Differences in biomarker levels before and after the 3-month intervention were tested within and between study groups. RESULTS: The lifestyle intervention resulted in a significant increase in OPG for participants in both the IG (q = 0.022) and CG (q = 0.002). sRANKL decreased significantly in the IG (q = 0.0464) and seemed to decrease in the CG (q = 0.5584). An increase in the intake of Omega-3 polyunsaturated fatty acids was significantly associated with an increase in OPG (r = 0.579, q = 0.045). Baseline serum levels of sRANKL were a strong predictor for the change of sRANKL in the course of the intervention (ß-estimate = - 0.70; q = 0.0018). Baseline physical fitness (assessed as VO2peak) might predict the change of OPG in the course of the intervention program (ß-estimate = 0.133 pg/ml/ml/min/kg; p = 0.0319; q = 0.2871). CONCLUSION: Findings from this pilot study seem to confirm our hypothesis by showing an increase in OPG and decrease in sRANKL over a 3-month lifestyle intervention and suggest that increased physical activity and adherence to the MedD are potent modulators of the biomarkers OPG and potentially sRANKL.

Therapeutic Effect of Matrine on Collagen-Induced Arthritis Rats and Its Regulatory Effect on RANKL and OPG Expression.

OBJECTIVE: To investigate the effect of matrine on rats with collagen-induced arthritis (CIA) and its regulatory effect on receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) expression. METHODS: Wistar rats (n = 6) and CIA rats (n = 30) were randomly divided into six groups: healthy, CIA control, low/medium/high matrine (25, 50, or 100 mg/kg, once per day for six weeks), and methotrexate (MTX) (2 mg/kg, once per week for six weeks). The degree of joint damage was evaluated by X-ray and HE staining. Bone marrow suppression was assessed by routine blood analysis. In addition, the levels of serum RANKL and OPG in the rats were measured by ELISA. RESULTS: The level of joint swelling and degree of joint damage assessed by ankle swelling measurements, AI score, X-ray, and HE staining were alleviated in the CIA rats treated with MTX or different doses of matrine. Furthermore, no obvious inhibitory effect was observed on the bone marrow of the CIA rats, regardless of the dose of matrine or treatment with 2 mg/kg MTX (P > 0.05). The levels of OPG in serum and the ratio of OPG/RANKL were higher, and RANKL expression was lower in the low/medium/high matrine group compared with that of the CIA control group. The serum levels of OPG and OPG/RANKL ratio increased with the matrine dose, while the opposite was observed for RANKL expression. CONCLUSION: Matrine treatment was associated with a lower degree of bone destruction, increased OPG expression and OPG/RANKL ratio, and decreased RANKL expression in CIA rats. Thus, matrine may represent a novel drug candidate for the treatment of RA.

Sclerostin and bone remodeling biomarkers responses to whole-body cryotherapy (- 110 °C) in healthy young men with different physical fitness levels.

We investigated the effects of single and repeated exposures to whole-body cryotherapy on biomarkers of bone remodeling and osteo-immune crosstalk: sclerostin, osteocalcin (OC), C-terminal cross-linked telopeptide of type I collagen (CTx-I), osteoprotegerin (OPG) and free soluble receptor activator for nuclear factor κ B ligand (sRANKL). The study included 22 healthy males, grouped in high physical fitness level (HPhL) and low physical fitness level (LPhL), all undergone 10 consecutive sessions in a cryogenic chamber (- 110 °C). We observed a significant time-effect on sclerostin (p < 0.05), OC (p < 0.01), CTx-I (p < 0.001), OC/CTx-I (p < 0.05), and significant differences in sRANKL between the groups (p < 0.05) after the 1st cryostimulation; a significant time-effect on OC (p < 0.001) and OC/CTx-I (p < 0.001) after the 10th cryostimulation, and a significant time-effect on CTx-I (p < 0.001) and OC/CTx-I (p < 0.01) after 10 sessions of WBC. In conclusion, in young men, the first exposure to extreme cold induced significant changes in serum sclerostin. The changes in sRANKL, between groups, suggest that fitness level may modify the body's response to cold. The effects of the first stimulus and the whole session are not identical, probably due to the physiological development of habituation to cold.

The Relationship between Serum and Gene Expression Levels of RANK, RANKL and Osteoprotegerin Inflammatory Pathway with Unstable Angina: A Case-control Study.

 Osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B (RANK) and receptor activator of nuclear factor-kappa B ligand (RANKL), the members of the tumor necrosis factor (TNF) family, have multiple effects on bone metabolism, endocrine functions and, as an inflammatory pathway, in the immune system. This study tried to determine the association of the OPG/RANKL/RANK axis with the severity of unstable angina (UA) as an inflammatory condition. Our study involved 50 patients with UA and 50 healthy people. Serum and peripheral blood mononuclear cells were isolated from all participants. Serum levels and gene expression of OPG, RANKL, and RANK in mononuclear cells were measured by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR), respectively. For each patient with UA, the thrombolysis in myocardial infarction (TIMI) and the global registry of acute coronary events (GRACE) scores were determined to evaluate the severity of the disease. Then we analyzed the relation of OPG, RANKL, and RANK levels with TIMI and GRACE scores in patients with UA. Discriminate analysis was used to predict the combinational models of such factors on the prediction of UA. Serum levels of OPG and RANKL (p<0.001) and gene expression of RANKL (p<0.001) were significantly more in patients than those in healthy ones. No relation was seen between the OPG/RANKL/RANK axis and the severity of UA according to TIMI and GRACE scores. Our study shows that serum level, as well as gene expression of OPG/RANKL/RANK axis neither, predicts the occurrence of UA nor shows any relationship with its severity.

Tocilizumab decreases T cells but not macrophages in the synovium of patients with rheumatoid arthritis while it increases the levels of serum interleukin-6 and RANKL.

OBJECTIVES: Our knowledge about the effect of tocilizumab (TCZ) on the synovium in rheumatoid arthritis (RA) is limited. The aim of this study was to investigate the effect of TCZ on citrullination and on inflammation in the synovial tissue and in the peripheral blood. METHODS: 15 patients with RA underwent synovial biopsy before and 8 weeks after TCZ initiation. Clinical evaluation was performed at baseline and at 8 weeks. Using immunohistochemistry, we evaluated the expression of CD68, CD3, CD20, osteoprotegerin (OPG) and receptor activator for nuclear factor-κB ligand (RANKL) before and after treatment with TCZ. We also analysed the expression of protein arginine deiminase (PAD)-2 and PAD-4 enzymes in the synovial tissue and protein citrullination patterns with the help of anticitrullinated protein antibody (ACPA) clones 1325:04C03 and 1325:01B09. Serum levels of interleukin-6 (IL-6), IL-8, RANKL, OPG and C-terminal crosslinked telopeptide type II collagen were measured by ELISA. Paired-wise Wilcoxon signed-rank test was used to compare median values before and after treatment. RESULTS: Disease activity in patients was reduced from baseline to 8 weeks. Although PAD-2 and PAD-4 expressions remained unchanged after TCZ treatment, the binding of one ACPA clone decreased in the synovial tissue. TCZ did not affect the number of CD68+ macrophages or CD20+ B cells but induced significant decrease in the number of CD3+ T cells. RANKL and OPG expression remained unchanged in the synovial tissue. A significant increase in the levels of IL-6 and RANKL was observed in the serum. This increase was statistically significant in patients who responded to TCZ (achieving Clinical Disease Activity Index low disease activity or remission) but not in non-responders. CONCLUSIONS: TCZ reduced synovial T-cell counts but not macrophages. A significant increase of serum IL-6 was observed in responders.

MicroRNA let-7i-3p affects osteoblast differentiation in ankylosing spondylitis via targeting PDK1.

Ankylosing spondylitis (AS) is a chronic autoimmune disease in which let-7i has been studied to involved. But, whether let-7i-3p could regulate osteoblast differentiation in AS remains unclear. This research targeted to decipher the impact of let-7i-3p on AS progression by modulating pyruvate dehydrogenase kinase 1 (PDK1). The bone mineral density of femur and lumbar vertebra and the maximum loading and bending elastic modulus of tibia, tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP)-3, osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in serum of AS mice, the pathological condition of synovial tissue were determined via let-7i-3p inhibitor and OE-PDK1 in animal experiment. Also, the cell viability and ALP activity were measured by let-7i-3p inhibitor and OE-PDK1 in cell experiments. let-7i-3p and PDK1 expression were detected. Let-7i-3p raised and PDK1 declined in AS mice. Depleted let-7i-3p and restored PDK1 increased bone mineral density and maximum loading and bending elastic modulus of tibia, reduced TNF-α, MMP-3 and RANKL contents, attenuated the pathological condition of synovial tissue and raised OPG content in AS mice. In cell experiments, up-regulating PDK1 and down-regulating let-7i-3p enhanced cell viability and ALP activity in AS mice. Low expression of let-7i-3p could enhance osteoblast differentiation in AS by up-regulating PDK1.Abbreviations: AS: Ankylosing spondylitis; PDK1: pyruvate dehydrogenase kinase 1; TNF-α: tumor necrosis factor-α MMP: matrix metalloproteinase; OPG: osteoprotegerin; RANKL: receptor activator of nuclear factor-κB ligand; miRNAs: MicroRNAs; BMD: bone mineral density; PFA: paraformaldehyde; NC: negative control; OE: overexpression; HE: Hematoxylin-eosin; PBS: phosphate-buffered saline; EDTA: ethylene diamine tetraacetic acid; DMEM: Dulbecco's Modified Eagle Medium; RT-qPCR: Reverse transcription quantitative polymerase chain reaction; GAPDH: glyceraldehyde phosphate dehydrogenase; UTR: untranslated region; WT: wild type; MUT: mutant type.

Relationship Between Maternal Bone Biomarkers and Fetal Adiposity Through Normal Pregnancy.

PURPOSE: To examine the association of maternal bone markers [sclerostin, soluble receptor activator of nuclear factor-κB ligand (sRANKL), osteocalcin, 25-hydroxyvitamin D3] with fetal intra-abdominal and subcutaneous adipose tissue deposition and birthweight during normal pregnancy. METHODS: One hundred pregnant women (aged 30.4 ±â€…5.6 years, mean ±â€…SD) with prepregnancy body mass index = 24.1 ±â€…4.6 kg/m2 were seen prospectively during each trimester. At each visit they were submitted to anthropometric measurements, a fasting blood sampling, a 75-g oral glucose tolerance test, and a fetal ultrasonogram. At birth, neonates had birth weight measurement. RESULTS: In the second trimester, maternal sclerostin concentrations correlated positively with fetal abdominal circumference and birth weight; maternal sRANKL concentrations correlated positively with fetal abdominal subcutaneous fat thickness, sagittal abdominal diameter, and abdominal circumference. Fetuses born to mothers with greater (>254 ng/mL), compared to fetuses born to mothers with lower (≤254ng/mL), sRANKL concentrations had greater abdominal circumference, sagittal diameter, and abdominal subcutaneous fat thickness. Maternal serum sclerostin concentrations were the best positive predictors of birth weight. In the third trimester maternal sclerostin concentrations correlated positively with fetal sagittal abdominal diameter; maternal sRANKL concentrations positively correlated with fetal abdominal circumference and fetal abdominal sagittal diameter. CONCLUSIONS: Maternal bone markers sclerostin and sRANKL may relate to fetal intra-abdominal adipose tissue deposition through as yet unknown direct or indirect mechanisms, thus contributing to birthweight.

Administration of zoledronic acid alleviates osteoporosis in HIV patients by suppressing osteoclastogenesis via regulating RANKL expression.

BACKGROUND: Osteoporosis is a common phenomenon in HIV patients on tenofovir treatment, but its underlying mechanisms remain to be explored. METHODS: Quantitative real-time PCR was performed to analyze the expression of miR-302, miR-101, miR-145 and osteoclast-specific genes in the serum of HIV patients treated with tenofovir and ZOL. ELISA was used to evaluate the expression of RANKL, SMAD3 and PRKACB in the serum of these patients. Luciferase assay was carried out to explore the inhibitory effects of miR-302, miR-101 and miR-145 on the expression of PRKACB, RANKL and SMAD3, respectively. Western blot was used to examine the expression of genes involved in NF­κB and JNK signaling pathways. RESULTS: ZOL treatment significantly suppressed the expression of CTx and osteocalcin in HIV patients treated with tenofovir. The BMD loss of HIV patients treated with tenofovir was effectively hindered by ZOL treatment. Mechanistically, the expression of miR-302, miR-101, miR-145, RANKL, SMAD3 and PRKACB in the serum was remarkably activated by ZOL treatment. Luciferase assays showed that miR-302, miR-101 and miR-145 effectively suppressed the expression of PRKACB, RANKL and SMAD3, respectively, through binding to their 3' UTR. Furthermore, ZOL treatment notably restored the normal expression of osteoclast­specific genes while activating NF­κB and JNK signaling pathways. CONCLUSION: The findings of this study demonstrated that administration of ZOL suppressed the expression of RANKL via modulating signaling pathways of miR-101-3p/RANKL, miR-302/PRKACB/RANKL and miR-145/SMAD3/RANKL. Furthermore, down-regulated expression of RANKL by ZOL treatment alleviated osteoporosis in HIV-positive subjects treated with tenofovir.

ETS1 polymorphism rs73013527 in relation to serum RANKL levels among patients with RA.

ABSTRACT: We previously identified E26 transformation specific sequence 1 (ETS1) rs73013527 single nucleotide polymorphism associated with RA susceptibility and disease activity. In the present study, we aims to further investigate the association between ETS1 rs73013527 and receptor activator of nuclear factor kappa B ligand (RANKL), an index related to bone destruction and was reported to elevate in RA.We determined genotypes of ETS1 rs73013527, serum RANKL concentration, clinical characteristics (disease duration, disease activity score for 28 painful/swollen joints), and laboratory markers (rheumatoid factor, anti-citrullinated protein antibody, anti-keratin antibody, c-reactive protein, erythrocyte sedimentation rate) of 254 RA cases. Univariate and multivariate analysis were employed to explore the association between ETS1 rs73013527 and serum RANKL levels in RA patients.Univariate and multivariate analysis indicated no association of serum RANKL levels with patient age, gender, clinical characteristics, and laboratory markers. Univariate analysis, not multivariate analysis indicated genotype CT/TT of ETS1 rs73013527 was significantly associated with elevated RANKL levels in RA patients.ETS1 rs73013527 is in relation to serum RANKL levels among patients with RA. ETS1 probably might be an indirect factors involved in RANKL regulation in RA.

Lumbar spine bone mineral density and trabecular bone score-adjusted FRAX, but not FRAX without bone mineral density, identify subclinical carotid atherosclerosis.

PURPOSE: Osteoporosis and atherosclerosis share common risk factors. Aim of this study was to test if FRAX (which is an algorithm that can identify subjects at risk of fracture), without or with BMD values, also adjusted for trabecular bone score (TBS) was able to identify subclinical atherosclerosis, evaluated by measurement of carotid intima media thickness (cIMT ≥ 0.9 mm) as compared to DXA values. METHODS: Ninety postmenopausal women underwent DXA measurement and cIMT evaluation. For each patient, the FRAX algorithm for major osteoporotic fracture (M) and for hip fracture (H) without BMD was computed, together with FRAX with BMD and TBS-adjusted FRAX. Serum levels of osteoprotegerin, sRANKL, and interleukin-6 were also measured. RESULTS: There were no differences in anthropometric parameters and cardiovascular risk factors between subjects with cIMT ≥ 0.9 mm (35% of subjects, group A) compared to those with cIMT < 0.9 mm (group B). The prevalence of osteoporosis and FRAX BMD, TBS-adjusted FRAX both for M and H were higher in group A compared to group B. The best ROC curves to identify subjects with a cIMT ≥ 0.9 mm were: lumbar spine T-score, with a threshold of - 2.5 SD (area under the curve, AUC 0.64; p = 0.02) with a sensibility of 50% and a specificity of 76%; TBS-adjusted FRAX H with a sensibility of 50% and a specificity of 72% (AUC 0.64; p = 0.01 with a threshold of 3%). Interleukin-6 positively correlated with FRAX BMD H and M. CONCLUSIONS: FRAX without BMD does not identify subclinical carotid atherosclerosis, while lumbar spine T-score and TBS-adjusted FRAX H similarly detected it with higher specificity for T-score.

Association of environmental cadmium exposure and bone remodeling in women over 50 years of age.

Chronic cadmium (Cd) toxicity is a significant health concern, and the mechanism of long-term low-dose Cd exposure on bone has not been fully elucidated yet. This study aimed to assess the association between long-term environmental Cd exposure and bone remodeling in women who aged over 50. A total of 278 non-smoking subjects from Cd-polluted group (n = 191) and non-Cd polluted group (n = 87) were investigated. Bone mineral density (BMD), the levels of three bone turnover markers (BTMs), including total procollagen type 1 amino-terminal propeptide (P1NP), collagen type 1 cross-linked C-telopeptide (ß-CTX), bone-specific alkaline phosphatase (BALP), together with serum soluble receptor activator of nuclear factor-κB ligand (sRANKL) and osteoprotegerin (OPG) were determined. Early markers of renal dysfunction were measured as well. Urinary Cd concentrations ranged from 0.41 to 87.31 µg/g creatinine, with a median of 4.91 µg/g creatinine. Age, BMD, T-score, and prevalence of osteoporosis showed no statistical differences among the quartiles of urinary Cd concentrations, while serum levels of P1NP, ß-CTX, and OPG were higher in the upper quartiles. Multivariate linear regression models indicated significantly positive associations of urinary Cd concentration with serum levels of P1NP, ß-CTX, BALP, sRANKL, and OPG. A ridge regression analysis with T-score and the three BTMs, sRANKL, and OPG, adjusted for age and body mass index (BMI), indicated that except for age and Cd exposure, ß-CTX was a predictor of T-score. These findings demonstrated that Cd may directly accelerate bone remodeling. Serum ß-CTX might be an appropriate biochemical marker for evaluating and monitoring Cd-related bone loss. Capsule: Cadmium (Cd) may directly accelerate bone remodeling and serum ß-CTX is a valuable biochemical marker for evaluating Cd-related bone loss.

Serum levels of osteoprotegerin, RANK-L & vitamin D in different stages of osteoarthritis of the knee.

Background & objectives: Osteoarthritis (OA) is the 11th leading cause of disability in the modern world, but till date, there have been no effective markers for monitoring the progression of OA. The three proteins RANK/RANK-Ligand and Osteoprotegerin (OPG) have been found to be the key regulators of bone metabolism. Interaction of RANK-Ligand with its receptor RANK triggers differentiation of osteoclasts leading to bone resorption. OPG on the other hand is protective as it is expressed by osteoblasts and bind RANKL with higher affinity preventing its interaction with RANK. The levels of these serum proteins are regulated by vitamin D and parathyroid hormones. Therefore, the present study, aimed to study the association of serum RANKL, OPG and vitamin D with disease severity in patients with knee OA. Methods: It was a cross-sectional study where 80 (43 women and 37 men) newly diagnosed subjects with OA knee were recruited. They were classified into four grades based on K-L grading and into two groups as early (grade 1+grade 2) and advanced (grade 3 + grade 4) based on the disease progression. Results: On comparing the biochemical parameters among the four grades decreasing vitamin D levels were seen with increasing severity of knee OA; an increasing trend of RANKL with increase in the severity of OA was seen; OPG was found to be elevated more in the early stages of OA. We also observed a strong association of RANKL/OPG ratio with disease severity. Interpretation & conclusions: Overall the results suggest that OPG may be considered as an early marker of the diseases.