OPG Concentrations Research Articles

Aging Influences Fracture Healing on the Cellular Level and Alters Systemic RANKL and OPG Concentrations in a Murine Model.

Clinical complications frequently follow polytrauma and bleeding fractures, increasing the risk of delayed fracture healing and nonunions, especially in aged patients. Therefore, this study examines age's impact on fracture repair with and without severe bleeding in mice. Young (17-26 weeks) and aged (64-72 weeks) male C57BL/6J mice (n=72 in total, n=6 per group) are allocated into 3 groups: the fracture group (Fx) undergoes femur osteotomy stabilized via external fixator, the combined trauma group (THFx) additionally receives pressure-controlled trauma hemorrhage (TH) and Sham animals are implanted with catheter and fixator without blood loss or osteotomy. Femoral bones are evaluated histologically 24h and 3 weeks post-trauma, while RANKL/OPG and β-CTx are measured systemically via ELISA after 3 weeks. Aging results in less mineralized bone and fewer osteoclasts within the fracture of aged mice in contrast to young groups after three weeks. Systemically, aged animals exhibit increased RANKL and OPG levels after fracture compared to their young counterparts. The RANKL/OPG ratio rises in aged Fx animals compared to young mice, with a similar trend in THFx groups. In conclusion, age has an effect during the later course of fracture healing on the cellular and systemic levels.

Can Vitamin D Reduce Inflammation? The Influence of Supplementation on Selected Immunological Markers.

There is increasing evidence that vitamin D (VitD) supplementation may reduce inflammation in individuals with multiple sclerosis (MS). The aim of this study was to evaluate the effect of different doses of VitD on selected markers of inflammation in patients with relapsing-remitting MS (RRMS). Participants were divided depending on the supplemented dose of VitD into a high-dose (2000 IU/d; HD) group and a low-dose (15,960 IU/month; LD) group (n = 23 and n = 29, respectively). The concentration of 25(OH)D and the levels of CXCL16, PTX3, ALCAM, IL-1RA, and OPG were measured initially and after six months of VitD supplementation in blood serum. A significant increase in the concentrations of CXCL16, PTX3, and OPG was observed during the study (p = 0.02, p = 0.01, and p < 0.01, respectively). Furthermore, a higher increase in PTX3 and OPG in the LD group was observed (p = 0.04 and p = 0.03, respectively). A significant positive correlation was observed between the 25(OH)D serum concentration and PTX3 (R = 0.28, p < 0.05) and OPG (R = 0.28, p < 0.05) only at the beginning of the study. In patients with RRMS, such doses of VitD might be too low to induce obvious beneficial effects on the pro-inflammatory and inflammatory balance.

Assessment of bone turnover markers and DXA parameters to predict bone metastasis progression during zoledronate treatment: a single-center experience

Bone metastases (BM) are a serious cancer complication, potentially causing substantial morbidity. Among the clinical issues related to BM, there is the lack of specific tools for early diagnosis and prognosis. We explored whether combining bone turnover markers (BTM) with dual-energy X-ray absorptiometry (DXA) assessment could identify early BM progression and risk of skeletal-related events (SREs) during zoledronate treatment. Before the initiation of zoledronate (T0) and after six months of treatment (T1), serum levels of five BTM were measured, and patients (N = 47) underwent DXA evaluation. Standard radiological imaging was performed to assess bone tumor response to medical anti-cancer treatment. High tumor burden in bone correlated with higher serum CTX (p = 0.007) and NTX (p = 0.005) at baseline. Low concentrations of OPG at T0 predicted BM progression with a sensitivity and specificity of 63% and 77%, respectively, when a cutoff of 5.2 pmol/l was used; such a predictive meaning was stronger in patients with lytic BM (sensitivity: 88%, specificity: 80%; p = 0.0006). As for the risk of SREs, we observed an association between low baseline OC (p = 0.04) and OPG (p = 0.08) and the onset of any-time SREs, whereas an increase in OPG over time was associated with reduced risk of on-study events (p = 0.03). Moreover, a statistically significant correlation emerged between low baseline lumbar T-score and femur BMD and on-study SREs (p < 0.001 in both instances). These findings suggest that addition of DXA to BTM dosage could help stratifying the risk of SREs at the time of BM diagnosis but does not enhance our capability of detecting bone progression, during zoledronate treatment.

The Effect of PCSK9 Inhibition on the Stabilization of Atherosclerotic Plaque Determined by Biochemical and Diagnostic Imaging Methods.

Atherosclerosis is a multifactorial, progressive, chronic inflammatory disease. Ultrasound and magnetic resonance imaging are the most accurate predictors of atherosclerotic plaque instability (MRI). Cytokines such as osteopontin, osteoprotegerin, and metalloproteinase 9 could be used as the most recent markers to identify and track the efficacy of anti-atherosclerotic therapy. Patients with USG and MRI-verified unstable atherosclerotic plaque were included in the study. Biomarker concentrations were measured and compared before and after PCSK9 inhibitor therapy. Additionally, concentrations prior to treatment were correlated with MRI images of the carotid artery. After treatment with alirocumab, the concentrations of MMP-9 (p < 0.01) and OPN, OPG (p < 0.05) decreased significantly. Furthermore, the results of OPN, OPG, and MMP 9 varied significantly depending on the type of atherosclerotic plaque in the MRI assay. In stable atherosclerotic plaques, the concentrations of OPN and OPG were greater (p < 0.01), whereas the concentration of MMP9 correlated with the instability of the plaque (p < 0.05). We demonstrated, probably for the first time, that alirocumab therapy significantly decreased the serum concentration of atherosclerotic plaque markers. In addition, we demonstrated the relationship between the type of atherosclerotic plaque as determined by carotid MRI and the concentration of these markers.

Relationship between circulating senescence-associated secretory phenotype levels and severity of type 2 diabetes-associated periodontitis: A cross-sectional study.

Senescence-associated secretory phenotype (SASP) has recently been found to drive comorbid diabetes and periodontitis by inducing a chronic, low-degree inflammatory state. Here, we sought to explore the relationship between circulating SASP and the severity of type 2 diabetes-associated periodontitis (DP). Eighty patients (middle-aged periodontitis, M-P group; aged periodontitis, A-P group; M-DP group; and A-DP group; n=20) provided gingival epithelium, serum, and periodontal clinical parameters. Circulating levels of 12 DP-related SASP factors were analyzed by immunoassay. Correlation between periodontal clinical parameters and circulating SASP levels was analyzed by Spearman's rank correlation coefficient and back propagation artificial neural network (BPNN). Senescence markers (p16, p21, and HMGB1) in gingiva were determined by immunofluorescence assay. M-DP group had increased serum levels of twelve SASP factors compared with the M-P group (p<0.5). Serum levels of IL-6, IL-4, and RAGE were higher in the A-DP group than the A-P group (p<0.5). The circulating concentrations of certain SASP proteins, including IL-1β, IL-4, MMP-8, OPG, RANKL, and RAGE were correlated with the clinical parameters of DP. BPNN showed that serum SASP levels had considerable predictive value for CAL of DP. Additionally, the DP group had higher expressions of p16, p21, and cytoplasmic-HMGB1 in the gingiva than the P group (p<0.5). Significantly enhanced circulating SASP levels and aggravated periodontal destruction were observed in patients with DP. Importantly, a non-negligible association between serum SASP levels and the severity of DP was found.

SHP-1 Protein Tyrosine Phosphatase Affects Early Postnatal Bone Development in Mice.

The Src homology region 2 domain-containing phosphatase-1 (SHP-1) is an intracellular tyrosine phosphatase that plays a negative regulatory role in immune cell signaling. Absent or diminished SHP-1 catalytic activity results in reduced bone mass with enhanced bone resorption. Here, we sought to investigate if Shp1 overexpression leads to increased bone mass and improved mechanical properties. Male and female wildtype (WT) and SHP1-transgenic (Tg) mice at 28, 56, and 84days of age were compared. We applied microcomputed tomography to assess femoral cortical bone geometry and trabecular architecture and 3-point mechanical bending to assess mid-diaphyseal structural and estimated material properties. Serum OPG, RANKL, P1NP, and CTX-1 concentrations were measured by enzyme-linked immunoassay. The majority of transgene effects were restricted to the 28-day-old mice. Trabecular bone volume per total volume, trabecular number, and connectivity density were greater in 28-day-old female SHP1-Tg mice when compared to WTs. SHP1-Tg female mice showed increased total and medullary areas, with no difference in cortical area and thickness. Cortical tissue mineral density was strongly genotype-dependent. Failure load, yield load, ultimate stress, and yield stress were all lower in 28-day-old SHP1-Tg females. In 28-day-old SHP1-Tg females, circulating levels of OPG and P1NP were higher and RANKL levels were lower than WT controls. Our study demonstrates a role for SHP-1 in early postnatal bone development; SHP-1 overexpression negatively impacted whole bone strength and material properties in females.

Eplerenone modulates the inflammatory response in monosodium iodoacetate-induced knee osteoarthritis in rats: Involvement of RANKL/OPG axis

AimsOsteoarthritis (OA) is a multifactorial degenerative disease marked by the progressive deterioration of articular cartilage with inflammation of the synovium. OA's main symptoms include pain and function loss. Monosodium Iodoacetate (MIA) experimental model is widely-used for OS induction since it produces symptoms comparable to those occurring in humans. Materials and methodsThirty-two rats were divided into four groups (n = 8). The 1st group received saline and included the normal-control rats. Groups 2–4 received intra-articular injections of MIA (3 mg/50 μL) in the rats' knee joints to induce OA. Group 2 included the MIA-control rats. Groups 3 and 4 received intra-articular MIA followed by a 14-day oral eplerenone (50 and 100 mg/kg); respectively. Key findingsIntra-articular injection of MIA in rats' knee joints caused significant inflammation and pain, elevation of Akt and ERK gene expression in knee joints along with significant alterations in the histological pictures of knee joints and OARSI scores. RANKL/OPG Axis was significantly disrupted. SignificanceEplerenone treatment produced a significant improvement in motor coordination and spontaneous locomotor activity in rats and modulated the key inflammatory mediators in OA (TNF-α, NF-κβ, and IL-6). Eplerenone also suppressed the qRT–PCR gene expression of Akt and ERK in knee joint tissues and improved the histological pictures and OARSI scores of knee joints of treated rats. Eplerenone caused a decline in RANKL concentration accompanied by a rise in OPG concentration thus modulating the RANKL/OPG Axis. Consequently, eplerenone is a candidate for OA therapy due to its potential anti-inflammatory effects.

ЦИТОКИНЫ И МАРКЕРЫ ЩИТОВИДНОЙ ЖЕЛЕЗЫ В СЫВОРОТКЕ КРОВИ У ЖЕНЩИН С АУТОИММУННЫМ ТИРЕОИДИТОМ В ДИНАМИКЕ ЛЕЧЕНИЯ

The study involved 147 women aged 31-47 with newly diagnosed AIT and hypothyroidism in the dynamics of replacement therapy with levothyroxine (before and after 6 months). The control group consisted of 63 conditionally healthy women, examined once at the beginning of the study. In peripheral blood serum, the concentrations of TNF-α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-17A, RANKL, OPG, TSH and TPOAb were determined.&#x0D; It was found that the initially increased values (p&lt;0,001) of IL-1β and IL-6 remained in patients after substitu- tion therapy at higher levels than in the control group (p&lt;0,001). The tendency to an increase in the levels of IL-10 (p=0,056) and IL-17A (p=0,067) revealed at the beginning of therapy was leveled out (p&gt;0,05) by the end of the ob- servation. TNF-α values did not significantly differ from those of the control group both at baseline and after 6 months&#x0D; (p=0,166 and p=0,184, respectively). The concentrations of IL-4 (p=0,376 and p=0,179, respectively), IL-8 (p=0,102 and p=0,116, respectively) and OPG (p=0,988 and p=0,661, respectively) remained at the level of the results of healthy women before and after treatment. RANKL concentrations before treatment were elevated (p=0,029), having lost their significant significance after therapy (p=0,096). The initially decreased values of the OPG/RANKL index (p=0,017) also did not differ on repeated examination from the indicators of the control group (p=0,253). After 6 months of taking levo- thyroxine in women with AIT, a significant (p&lt;0,001) decrease in initially elevated TSH levels to the values characteris- tic of the control group was recorded against the background of a significant (p&lt;0,001) increase in the concentrations of initially elevated autoimmune antibodies (p&lt;0,001).&#x0D; When examining women with AIT and confirmed hypothyroidism, it was found that replacement therapy with levothyroxine for 6 months did not significantly affect the production of most of the studied cytokines against the back- ground of a decrease in the initially increased TSH values to the values of the control group and a significant increase in the initially increased TPOAb.

Bone remodeling serum markers in children with systemic lupus erythematosus

IndroductionSLE is an autoimmune multisystem disease. Glucocorticoid is an irreplaceable medication for SLE. Glucocorticoid and inflammatory mediators impact bone remodeling by OPG/RANKL/RANK signal system, which could lead to osteoporosis. Our aim is to detect the expression of RANKL/OPG in children with SLE, and to preliminarily explore the changes of bone remodeling serum markers in children with SLE.MethodsSerum RANKL and OPG of 40 children with SLE and healthy children were detected by ELISA, while 25(OH)VitD3 was detected routinely. Clinical data of children with SLE were recorded, including gender, age, height, weight, BMI, SLEDAI, duration of the disease, cumulative dose of glucocorticoid, and correlation analysis was conducted with RANKL, OPG and 25(OH)VitD3.ResultsSerum RANKL concentrations in SLE group were significantly higher than health group (9.82 ± 7.20 vs. 6.80 ± 4.35 pg/ml and 0.081 ± 0.072 vs. 0.042 ± 0.034, P < 0.05) respectively, and the concentrations of OPG and 25(OH)VitD3 in serum were significantly lower than health group (156.34 ± 57.33 vs. 189.16 ± 68.70 pg/ml and 43.66 ± 31.27 vs. 59.04 ± 21.56 mmol/L, P < 0.05). Serum RANKL in children with SLE was positively correlated with the duration of SLE, cumulative dose of GC(r = 0.593, 0.727, P < 0.05). And it was negatively correlated with serum OPG and 25(OH)VitD3 (r = -0.601, -0.469, P < 0.05). In addition, serum OPG and 25(OH)VitD3 concentrations were inversely correlated with cumulative dose of GC (r = -0.66, -0.508, P < 0.05).ConclusionLow levels of vitamin D3 and bone metabolic abnormalities still persist in children with SLE even if the disease is in remission, while serum RANKL level was elevated, OPG expression was reduced. In the case of disease remission, GC is involved in the occurrence and development of abnormal bone remodeling through RANKL/OPG.

The Neuropeptide VIP Limits Human Osteoclastogenesis: Clinical Associations with Bone Metabolism Markers in Patients with Early Arthritis.

We aimed to evaluate the direct action of VIP on crucial molecules involved in human osteoclast differentiation and function. We also investigated the relationship between VIP serum levels and bone remodeling mediators in early arthritis patients. The expression of VIP receptors and osteoclast gene markers in monocytes and in vitro differentiated osteoclasts was studied by real-time PCR. NFATc1 activity was measured using a TransAM® kit. Osteoclastogenesis was confirmed by quantification of tartrate-resistant acid phosphatase positive multinucleated cells. OsteoAssay® Surface Multiple Well Plate was used to evaluate bone-resorbing activity. The ring-shaped actin cytoskeleton and the VPAC1 and VPAC2 expression were analyzed by immunofluorescence. We described the presence of VIP receptors in monocytes and mature osteoclasts. Osteoclasts that formed in the presence of VIP showed a decreased expression of osteoclast differentiation gene markers and proteolytic enzymes involved in bone resorption. VIP reduced the resorption activity and decreased both β3 integrin expression and actin ring formation. Elevated serum VIP levels in early arthritis patients were associated with lower BMD loss and higher serum OPG concentration. These results demonstrate that VIP exerts an anti-osteoclastogenic action impairing both differentiation and resorption activity mainly through the negative regulation of NFATc1, evidencing its bone-protective effects in humans.

Role of Interleukin- 34 together with Receptor Activator of Nuclear Factor kB ligand and Osteoprotegrin levels in Periodontal Disease

Aim: To compare the levels and relative ratios of Interleukin-34, osteoprotegrin, and factor kB ligand in the crevicular fluid of individuals with periodontal disease. Study design &amp; setting: Randomized Clinical Trial, Frontier Medical And Dental College, Abbotabad Methodology: We enrolled 15 healthy subjects (Group I), 15 patients with chronic periodontal disease (Group II) and 15 patients with aggressive periodontal disease (Group III). At baseline and six weeks after NSPT, crevicular fluid and clinical measures were made. The GCF IL-34, factor kB ligand, and osteoprotegrin levels were measured by using ELISA and their relative ratios were computed. Result: Group II and III had significantly higher crevicular fluid IL-34 and factor kB ligand levels than the Control group (I), although crevicular fluid with osteoprotegrin levels was significantly decreased (P&lt;0.05). GCF, IL-34, and RANKL levels reduced in Groups II and III six weeks after NSPT, although OPG concentrations increased statistically (P&lt;0.05). Significantly positive association was observed between IL-34 and factor kB ligand, clinical attachment level, and gingival index, but not with osteoprotegrin. Conclusion: Gingival crevicular fluid IL-34 levels were elevated in individuals with periodontal disease and lowered during non surgical intervention, and its levels correlated positively with the factor kB ligand and osteoprotegrin ratios, clinical attachment level, and gingival index. Keywords: Periodontitis, IL-34, osteoprotegrin

Biologization of Pcl-Mesh Using Platelet Rich Fibrin (Prf) Enhances Its Regenerative Potential In Vitro.

Introduction: Resorbable synthetic scaffolds are promising for different indications, especially in the context of bone regeneration. However, they require additional biological components to enhance their osteogenic potential. In addition to different cell types, autologous blood-derived matrices offer many advantages to enhance the regenerative capacity of biomaterials. The present study aimed to analyze whether biologization of a PCL-mesh coated using differently centrifuged Platelet rich fibrin (PRF) matrices will have a positive influence on primary human osteoblasts activity in vitro. A polymeric resorbable scaffold (Osteomesh, OsteoporeTM (OP), Singapore) was combined with differently centrifuged PRF matrices to evaluate the additional influence of this biologization concept on bone regeneration in vitro. Peripheral blood of three healthy donors was used to gain PRF matrices centrifuged either at High (710× g, 8 min) or Low (44× g, 8 min) relative centrifugal force (RCF) according to the low speed centrifugation concept (LSCC). OP-PRF constructs were cultured with pOBs. POBs cultured on the uncoated OP served as a control. After three and seven days of cultivation, cell culture supernatants were collected to analyze the pOBs activity by determining the concentrations of VEGF, TGF-β1, PDGF, OPG, IL-8, and ALP- activity. Immunofluorescence staining was used to evaluate the Osteopontin expression of pOBs. After three days, the group of OP+PRFLow+pOBs showed significantly higher expression of IL-8, TGF-ß1, PDGF, and VEGF compared to the group of OP+PRFHigh+pOBs and OP+pOBs. Similar results were observed on day 7. Moreover, OP+PRFLow+pOBs exhibited significantly higher activity of ALP compared to OP+PRFHigh+pOBs and OP+pOBs. Immunofluorescence staining showed a higher number of pOBs adherent to OP+PRFLow+pOBs compared to the groups OP+PRFHigh+pOBs and OP+pOBs. To the best of our knowledge, this study is the first to investigate the osteoblasts activity when cultured on a PRF-coated PCL-mesh in vitro. The presented results suggest that PRFLow centrifuged according to LSCC exhibits autologous blood cells and growth factors, seem to have a significant effect on osteogenesis. Thereby, the combination of OP with PRFLow showed promising results to support bone regeneration. Further in vivo studies are required to verify the results and carry out potential results for clinical translation.

The heparan sulfate proteoglycan Syndecan-1 influences local bone cell communication via the RANKL/OPG axis

The heparan sulfate proteoglycan Syndecan-1, a mediator of signals between the extracellular matrix and cells involved is able to interact with OPG, one of the major regulators of osteoclastogenesis. The potential of osteoblasts to induce osteoclastogenesis is characterized by a switch of OPG (low osteoclastogenic potential) towards RANKL production (high osteoclastogenic potential). In the present study, we investigated the influence of endogenous Syndecan-1 on local bone-cell-communication via the RANKL/OPG-axis in murine osteoblasts and osteoclasts in wild type and Syndecan-1 lacking cells. Syndecan-1 expression and secretion was increased in osteoblasts with high osteoclastogenic potential. Syndecan-1 deficiency led to increased OPG release by osteoblasts that decreased the availability of RANKL. In co-cultures of Syndecan-1 deficient osteoblasts with osteoclast these increased OPG in supernatant caused decreased development of osteoclasts. Syndecan-1 and RANKL level were increased in serum of aged WT mice, whereas Syndecan-1 deficient mice showed high serum OPG concentration. However, bone structure of Syndecan-1 deficient mice was not different compared to wild type. In conclusion, Syndecan-1 could be regarded as a new modulator of bone-cell-communication via RANKL/OPG axis. This might be of high impact during bone regeneration or bone diseases like cancer where Syndecan-1 expression is known to be even more prevalent.

Niveles de citoquinas quimiotácticas de linfocitos B y Th17 en el fluido crevicular periimplantario de pacientes con implantes sanos, perimucositis y periimplantitis.

Peri-implantitis is one of the leading causes of implant failure and loss, and its early diagnosis is not currently feasible due to the low sensitivity of currents methods. In the current exploratory cross-sectional study, we explored the diagnostic potential of lymphocyte B and Th17-chemotactic cytokine levels in peri-implant crevicular fluid (PICF) in 54 patients with healthy, peri-mucositis, or peri-implantitis implants. Peri-implant crevicular fluid was collected, and the levels of the molecules under study were quantified by Luminex assay. The concentrations of CCL-20 MIP-3 alpha, BAFF/BLYS, RANKL and OPG concentration in PICF were analyzed in the context of patient and clinical variables (smoking status, history of periodontitis, periodontal diagnosis, implant survival, suppuration, bleeding on probing, periodontal probing depth, clinical attachment level, mean of implant probing depth, and plaque index). Patients with peri-implantitis, appear to have an overregulation of the RANKL/BAFF-BLyS axis. This phenomenon needs to be investigated in depth in further studies with a larger sample size.

Extracellular Matrix Remodeling Factors as Markers of Carotid Artery Atherosclerosis.

Materials and Methods 20 patients undergoing routine carotid endarterectomy and 40 healthy volunteers were enrolled in this study. MMPs activity and OPG and FN concentrations were measured in atherosclerotic plaques and nonchanged contiguous tissue after homogenization as well as in plasma from patients and reference group. The activity of MMPs was evaluated by gelatin zymography, and the concentration of OPG and FN was assessed by ELISA. Results OPG concentration and MMP-9 activity showed differences between plaque and nonchanged tissue; OPG was higher in adjacent tissue (P=0.0009), whereas MMP-9 was higher in plaque (proMMP-9 P=0.0003; MMP-9 P < 0.0001). The OPG plasma concentration and both MMPs plasma activity were higher in patients (OPG P < 0.001; proMMP-2 P=0.0292; and proMMP-9 P=0.0374), while FN plasma concentration was lower in patients than in the reference group (P=0.0004). The ROC curves analysis showed the highest AUC for OPG (0.943) with 85.0% sensitivity and 92.1% specificity. Conclusions The atherosclerotic plaque and the contiguous artery wall are biochemically different. OPG shows the highest potential to be a marker of advanced carotid atherosclerosis.

Association of serum osteoprotegerin and osteoprotegerin gene polymorphism with subclinical carotid artery atherosclerosis and disease activity in rheumatoid arthritis patients

Aim of the workTo investigate the association of single nucleotide polymorphism (SNP) (rs2073618) of the OPG gene and of serum OPG with subclinical carotid atherosclerosis in RA patients. Patients and methodsEighty RA patients with no previous history of a cardiovascular disease were studied and forty healthy controls were enrolled in the study. Carotid atherosclerosis was evaluated by high-resolution B-mode ultrasound and the carotid intimal medial thickness (CIMT) measured. rs2073618 OPG genotyping was performed by polymerized chain reaction (PCR) and serum OPG concentrations were measured. The high sensitive C reactive protein (hs-CRP), rheumatoid factor (RF) titer and anti-cyclic citrullinated peptide (anti-CCP) were assessed. The disease activity score (DAS28) was evaluated. ResultsThe patients mean age was54.1 ± 6.2 years, disease duration of 12.5 ± 8.5 years and were 72 females and 8 males. Increased IMT was found in 38 patients, 40 age and sex matched controls were included. Patients with atherosclerosis (n = 38) had longer disease duration, higherDAS28, hs-CRP, RF titer and anti-CCP. The serum OPG levels were higher in patients with atherosclerosis (1106.4 ± 1157.1 ng/l) compared to those without (658.3 ± 151.1 ng/l)(p = 0.001). Serum OPG significantly correlated with disease duration (r = 0.42, p = 0.005), DAS28 (r = 0.53, p = 0.001), hs-CRP (r = 0.41, p = 0.007), anti-CCP (r = 0.47, p = 0.003) and mean CIMT (r = 0.37, p = 0.02). The frequencies of CC, CG and GG genotypes were comparable between those with and without atherosclerosis (39.5%, 50%, 10.4% vs 42.9%, 47.6% and 9.5% respectively). Conclusionrs2073618 OPG gene may not be associated with subclinical atherosclerosis, although the serum level could be a reliable marker for disease activity and for early detection of carotid artery atherosclerosis in RA.

Metabolic bone markers can be related to preserved insulin secretion in children with newly diagnosed type 1 diabetes.

Type 1 diabetes (T1D) may be associated with numerous complications including bone metabolism disorders. The aim of the study was to evaluate the bone metabolism markers twice in children with a newly diagnosed T1D and after an average of seven months of its duration in relation to parameters of the clinical course of diabetes. In 100 T1D patients and 52 control subjects, the following bone turnover markers were evaluated: osteocalcin - OC, osteoprotegerin - OPG, sRANKL, and deoxypyridoline in urine - DPD and DXA examination was also performed. Lower OC concentration at T1D onset in comparison to controls (p < 0.001) and its increase during follow-up (p < 0.001) was ob-served. The OPG concentration was elevated at T1D onset as compared to the control group (p = 0.024) and decreased thereafter (p < 0.001). The s-RANKL level increased during follow-up (p < 0.001) and was lower than in controls (p < 0.001). Urine DPD con-centration also increased during follow-up in the T1D patient group (p < 0.001) and was higher in comparison to the control group (p = 0.021). BMD-TBLH was higher in the control group as compared to patients both at T1D onset (p = 0.025) and in follow-up ob-servation (p = 0.034). Moreover, OPG correlated positively with glycated haemoglobin (HbA1c) (p = 0.004) and negatively with fasting C-peptide level (p = 0.046) and BMI Z-score (p = 0.003), whereas s-RANKL correlated positively with both fasting (p < 0.001) and stimulated C-peptide levels (p < 0.001). Bone metabolism disorders observed at T1D onset in children and modified after reaching the metabolic control of the disease seem to be most strongly associated with preserved insulin secretion.

Quantifying RANKL and OPG levels in healthy children: A large cross-sectional analysis.

There have been new advances in understanding bone remodeling on a molecular level including the RANKL-OPG pathway, leading to advancements in targeted therapeutic intervention. There is however limited data in pediatrics with little known on normative values in healthy children. This is the largest cohort to quantify RANKL, OPG, and RANKL: OPG levels in healthy children as well as study the influence of age, gender, Tanner stage, and BMI in this population. Healthy subjects, 1-21 years of age, were recruited from general pediatric clinics affiliated with CHLA and in collaboration with samples stored from a previously completed study. Healthy children were defined as those with no chronic disease, daily medication, or fractures in the past six months. Free soluble RANKL and OPG levels were quantified using a sandwich ELISA. Three hundred samples were collected with overall serum concentrations of RANKL, OPG and RANKL: OPG of 0.28 pmol/L, 3.56 pmol/L and 0.08 pmol/L, respectively. Serum RANKL and RANKL: OPG concentrations were significantly different by age (p = 0.0001 and 0.0027, respectively). There was an overall downward trend by age except in the 11-15-year age group where a slight increase was noted. RANKL concentrations were also significantly different between Tanner stages, with highest concentrations seen at Tanner 3 (p = 0.0481), and zBMI (p = 0.001). OPG was inversely correlated with zBMI, but not influenced by gender, age, or Tanner stage. We showed significant difference in RANKL levels by age, Tanner stage, and zBMI. OPG was inversely correlated with zBMI. Insight into circulating levels of RANKL, OPG and RANKL: OPG in healthy children may be a potential tool to better understand disease states in pediatrics. Future studies are needed to evaluate the clinical significance of RANKL and OPG levels for diagnostic and therapeutic purposes in this population.

Effect of Prenatal and Postpartum Vitamin D Supplementation on Circulating Biomarkers of Maternal Bone Metabolism (P24-048-19)

ObjectivesTo estimate the dose-dependent effect of prenatal and postpartum vitamin D supplementation on circulating concentrations of biomarkers of maternal bone formation (osteoprotegerin [OPG], osteocalcin [OC], procollagen type 1 amino-terminal propeptide [P1NP], and OPG/RANKL ratio), bone resorption (receptor activator nuclear factor kappa-β ligand [RANKL], and carboxyterminal telopeptide of type 1 collagen [CTX]), and general markers of bone metabolism (fibroblast growth factor 23 [FGF23]), in a pregnancy cohort in Dhaka, Bangladesh. MethodsThis study is a sub-study of the Maternal Vitamin D for Infant Growth trial, a randomized controlled trial in which women were enrolled at 17–24 weeks gestation and randomized to one of five weekly oral vitamin D3 supplements or placebo regimens during pregnancy and up to 6 months postpartum: group A (placebo), group B (4200 IU/week), group C (16,800 IU/week), group D (28,000 IU/week), group E (28,000 IU/week during pregnancy and postpartum). Postpartum, all groups other than group E received placebo. Maternal venous blood samples were collected from MDIG participants at enrolment, delivery and 6 months postpartum. Concentrations of FGF23, CTX, and P1NP were determined using ELISAs and OPG, OC, and RANKL concentrations were determined using a Luminex/Millipore magnetic beads kit. For each biomarker (n range, 344 to 606), linear regression was used to compare each treatment group versus the placebo group adjusting for baseline concentrations. For delivery time point analyses, treatment groups D and E (same prenatal vitamin D dose) were combined, while in postpartum analyses the two groups were separated to estimate the postpartum effect. ResultsAt delivery and 6 months postpartum, there were no significant differences in OPG, OC, OPG/RANKL, RANKL, and FGF23 concentrations between each treatment group versus the placebo group (Table 1 and Table 2). ConclusionsVitamin D supplementation during the 2ndhalf of pregnancy and up to 6 months postpartum had no effect on markers of bone formation or resorption. Analyses for CTX are underway and will also be presented. Funding SourcesBill and Melinda Gates Foundation. Supporting Tables, Images and/or Graphs▪▪▪

Effects of 12-week combined exercise on RANKL/RANK/OPG signaling and bone-resorption cytokines in healthy college females.

[Purpose]The OPG/RANK/RANKL signaling is a new family of bone metabolism biomarkers belonging to the immune system. However, the bone metabolism response to long-term exercise in the RANKL/RANK/OPG signaling is less evident. The purpose of this study was to examine these biomarkers in healthy college females after 12-weeks combined exercise intervention.[Methods]Participants (N=22, 22.4±1.3yrs) were randomly divided in two different group: 12 in the control group and 10 in the exercise group performing combined exercise program that interventions was conducted 3 times per week for 12 weeks. The outcome measures included serum concentrations of RANKL, OPG and bone metabolic cytokines such as TNF-α and IL-6, and mRNA expressions of same variables from PBMC. VO2max and bone mineral density (BMD) were measured at before and after exercise intervention.[Results]There were no significant differences in the serum RANKL, OPG concentrations and all RANKL/RANK/OPG signaling mRNA expression on interaction effect between group and time (NS). Also no significant differences were found in the serum TNF-α and IL-6 concentrations and mRNA expression (NS). The IL-6 mRNA expression only showed significant difference in the main effect of groups (p<.05). There were also no significant differences in the VO2max and BMD on interaction effect between group and time (NS).[Conclusion]These results suggested that there were no effects on bone mineral density and RANKL/RANK/OPG signaling without the effect of 8-weeks combined exercise on cardiovascular endurance fitness.