Receptor Activator Of Nuclear factor-κB Ligand Research Articles

IL-15 deficiency alleviates steroid-induced osteonecrosis of the femoral head by impact osteoclasts via RANKL-RANK-OPG system

BackgroundWhether IL-15 is involved in the development of steroid-induced osteonecrosis of the femoral head (ONFH) is investigated.MethodsC57BL/6 J and l15−/−mice were injected with methylprednisolone to induce wide type osteonecrosis (WT ON) and IL-15 deficiency osteonecrosis (IL-15−/− ON). Hematoxylin-Eosin (H&E) staining and micro-computed tomography (micro-CT) scanning was used to detect the microstructure. The differentiation and formation of osteoclasts were determined with colony-forming unit-granulocyte macrophages (CFU-GM), colony-forming unit-macrophage/mononuclear (CFU-M) per tibia, and tartrate-resistant acid phosphatase (TRACP or TRAP) positive cells. Serum interleukin (IL)-15, osteocalcin, bone alkaline phosphatase (BAP), bone Gla protein (BGP), and TRACP were assayed with enzyme-linked immunosorbent assay (ELISA). The receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) in the femoral heads were detected by Western blot. CD34 staining was performed to detect microvascular density.ResultsIL-15 secretion was increased in the femoral heads and the serum of steroid-induced ONFH mice. IL-15 deficiency may lead to up-regulated vessel remodeling, improved microstructure, and up-regulated serum osteocalcin, BAP, and BGP secretion. Both the expression of RANKL/RANK/OPG and osteoclast differentiation and formation can be down-regulated by IL-15 deficiency.ConclusionIL-15 deficiency alleviates steroid-induced ONFH by impact osteoclasts via RANKL-RANK-OPG system.

Management of medication-related osteonecrosis of jaw: Comparison between icariin and teriparatide in a rat model.

The aim of this study is to compare the effects of icariin and teriparatide on the treatment of medication-related osteonecrosis of the jaw (MRONJ) using a rat model. Fifty rats undergoing ovariectomy were randomly assigned to control group (n=10) and the MRONJ model group (n=40). Zoledronic acid (0.2mg/kg) and dexamethasone (2mg/kg) were injected into rats in the model group for 8weeks while saline was applied in control group, then all rats underwent tooth extraction and bone defect. Eightweeks later, rats diagnosed with MRONJ (n=33) were randomly distributed to icariin (n=11), teriparatide (n=11), and the untreated (n=11) group, and rats received daily 150mg/kg icariin, 20µg/kg teriparatide, and no intervention, respectively, for 8weeks. Then, mandibulars were dissected for later examination. Rats diagnosed with MRONJ (33/40) demonstrated significantly larger area of soft tissue wound and necrotic bone with higher ratio of empty bone lacuna. Area of soft tissue wound and ratio of empty bone lacuna were significantly decreased in the icariin group compared with the untreated group, while teriparatide group revealed significantly higher ratio of receptor activator of NF-kB ligand (RANKL)-positive osteocytes, smaller area of necrotic bone and lower ratio of empty lacuna. The two agents were related to higher expression of BMP-2 in osteocytes but were not statistically significant. Icariin benefits MRONJ in terms of the area of soft tissue wound and ratio of empty lacuna. Teriparatide activates expression of RANKL and reduces the area of bone necrosis and ratio of empty lacuna in a MRONJ lesion. The data suggest possible healing improvement in patients with MRONJ and further studies to prove the efficacy of icariin.

Premenopausal Plasma Osteoprotegerin and Breast Cancer Risk: A Case-Control Analysis Nested within the Nurses' Health Study II.

Emerging evidence supports a role of the receptor activator of NF-κB (RANK) pathway in normal mammary gland development and breast carcinogenesis. Osteoprotegerin (OPG) is the endogenous decoy receptor for RANK-ligand (RANKL), which inhibits RANK-signaling. Whether OPG may be a biomarker of breast cancer risk remains unclear. We evaluated the association between plasma OPG and breast cancer risk in a case (n = 297)-control (n = 297) study nested within the Nurses' Health Study II. Cases were women who were cancer-free and premenopausal at blood collection who developed invasive breast cancer. OPG was quantified using an ELISA. Conditional logistic regression was used to estimate multivariable odds ratios (OR) and 95% confidence intervals (CI) for the association between OPG levels and breast cancer risk, adjusting for potential confounders. Unconditional logistic regression, additionally adjusting for matching factors, was used for stratified analyses. Overall, there was no substantial evidence for an association between plasma OPG levels and breast cancer risk, although the point estimate for the highest (vs. lowest) quartile was below 1 (OR = 0.78; 95% CI, 0.46-1.33; P trend = 0.30). There was no evidence of heterogeneity by various reproductive, hormonal, or tumor characteristics, including hormone receptor status and grade (all P heterogeneity ≥ 0.17). Findings from this prospective study do not provide substantial evidence for an association between circulating OPG and breast cancer risk among premenopausal women; however, we were underpowered in stratified analyses. Results do not provide strong evidence for OPG as a potential biomarker of breast cancer risk among premenopausal women.

Bone mineral density and mortality in end-stage renal disease patients.

Osteoporosis characterized by low bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is common among end-stage renal disease (ESRD) patients and associates with high fracture incidence and high all-cause mortality. This is because chronic kidney disease-mineral bone disorders (CKD-MBDs) promote not only bone disease (osteoporosis and renal dystrophy) but also vascular calcification and cardiovascular disease. The disturbed bone metabolism in ESRD leads to ‘loss of cortical bone’ with increased cortical porosity and thinning of cortical bone rather than to loss of trabecular bone. Low BMD, especially at cortical-rich bone sites, is closely linked to CKD-MBD, vascular calcification and poor cardiovascular outcomes. These effects appear to be largely mediated by shared mechanistic pathways via the ‘bone–vascular axis’ through which impaired bone status associates with changes in the vascular wall. Thus, bone is more than just the scaffolding that holds the body together and protects organs from external forces but is—in addition to its physical supportive function—also an active endocrine organ that interacts with the vasculature by paracrine and endocrine factors through pathways including Wnt signalling, osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/RANK ligand system and the Galectin-3/receptor of advanced glycation end products axis. The insight that osteogenesis and vascular calcification share many similarities—and the knowledge that vascular calcification is a cell-mediated active rather than a passive mineralization process—suggest that low BMD and vascular calcification (‘vascular ossification’) to a large extent represent two sides of the same coin. Here, we briefly review changes of BMD in ESRD as observed using different DXA methods (central and whole-body DXA) at different bone sites for BMD measurements, and summarize recent knowledge regarding the relationships between ‘low BMD’ and ‘fracture incidence, vascular calcification and increased mortality’ in ESRD patients, as well as potential ‘molecular mechanisms’ underlying these associations.

Baicalin inhibits root resorption during tooth movement in a rodent model

ObjectiveBaicalin mediates bone metabolism and has shown protective activity against periodontal tissue damage in a rat model of periodontitis. Therefore, we hypothesized that baicalin may inhibit the root resorption that occurs during orthodontic tooth movement and examined its effect on the histological changes in periodontal tissue that occur during tooth movement. MethodsFirst molars of rats were subjected to traction using excessive orthodontic force to produce a root resorption model. Rats in the baicalin group received baicalin for 3 weeks during tooth movement, and the amount of first molar movement on day 21 after the initiation of traction was measured by three-dimensional micro-computed tomography analysis. After tooth movement, tissue samples from the mesial and tension sides were collected, and successive horizontal sections were prepared and examined using hematoxylin–eosin and tartrate-resistant acid phosphatase (TRAP) staining and immunohistochemical staining for the receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG). The severity of root resorption was also determined by histological analysis. ResultsThere was no significant intergroup difference in tooth movement during the experimental exaggerated tooth movement. In comparison with the control group, the baicalin-treated group showed increased OPG expression, suppressed RANKL expression, and significantly fewer TRAP-positive cells in the first molars. The root resorption area was significantly smaller in the baicalin group. ConclusionsTreatment with baicalin prevented root resorption without preventing tooth movement. Baicalin may be useful for the management of root resorption during orthodontic treatment.

Histomorphometric Analysis of Pre- and Post-Denosumab-Treated Giant Cell Tumor of Bone.

Context. Denosumab is a monoclonal antibody against RANK ligand. Its administration in giant cell tumor of bone (GCTB) cases results in elimination of giant cells and new bone formation. Neoplastic stromal cells of GCTB harbor mutation of histone 3.3 and have pre-osteoblastic properties and thus express SATB2. Objectives. To (1) analyze histological changes in post-denosumab-treated GCTB, (2) analyze expression of H3.3G34W and SATB2 in pre- and post-denosumab-treated samples, and (3) to discuss why changes occur in the expression of not only H3.3G34W but also SATB2. Materials and Methods. Hematoxylin and eosin slides of 19 cases of denosumab-treated GCTB were reviewed. Immunohistochemical stains H3.3G34W and SATB2 were performed. The number of positive mononuclear cells were counted and graded. Results. Complete absence of osteoclast-like giant cells (OCLGCs) was noted in most cases along with a fibro-osseous component merging with peripheral shell of reactive bone. Irregular trabeculae of woven bone and osteoid with focal osteoblastic rimming was seen. Spindle cells were arranged predominantly in fascicular pattern. Morphometric analysis of H3.3G34W showed a mean of 68.8% positive stromal cells in pretreatment and a mean of 26.9% positive stromal cells in posttreated specimens with a statistically significant P value (.001). Mean percentage of SATB2-positive stromal cells in the pre- and posttreatment specimens was 36.46% and 20.8%, respectively. Conclusions. Our study validates that denosumab treatment results in marked reduction of OCLGCs with increased osteoblastic activity. Decreased expression of H3.3G34W in posttreatment may be a result of decreased antigenicity of neoplastic mononuclear cells. No significant change in SATB2 expression was noted.

In vitro tripanocidal effect of 1,8-dioxooctahydroxanthenes (xanthenodiones) and tetraketones and improvement of cardiac parameters in vivo

ObjectiveTrypanosoma cruzi infection affects millions of people worldwide, and the drugs available for its treatment have limited efficacy. 1,8-Dioxooctahydroxanthenes and tetraketones are compounds with important biological applications. The aim of this study was to assess the trypanocidal and inflammatory activities of nine 1,8-dioxooctahydroxanthenes (1–9) and three tetraketones (10–12). Methods and resultsBy in vitro killing assay, three compounds were able to eliminate CL TdTomato expressing strain of T. cruzi, 9 (IC50=30.65μM), 10 (IC50=14.11μM), and 11 (IC50=26.43μM). However, only 9 was not toxic to Vero cells. Next, to evaluate the in vivo antitrypanosomal and immunological efficacy of 9, Swiss mice were infected with the Y and CL strains of T. cruzi and treated for 10 days with 50mg/kg of 9. This compound reduced the cardiac inflammatory infiltration in animals infected with both strains. Rank's ligand (RankL), CCL2, and interferon (IFN)-γ were measured in the cardiac tissue homogenate of the Y-strain-infected animals, and no interference of 9 was observed. However, compound 9 increased the RankL and interleukin (IL)-10 levels in CL-infected mice. No hepatic and renal toxicity was observed. ConclusionOur findings showed that 1,8-dioxooctahydroxanthene has antiparasitic effect and ameliorates the cardiac inflammatory parameters related to T. cruzi infection.

RANK Ligand Helps Immunity to Leishmania major by Skewing M2-Like Into M1 Macrophages.

Macrophages host Leishmania major infection, which causes cutaneous Leishmaniasis in humans. In the murine model, resistance to infection depends on the host immunity mediated by CD4 T-cell cytokines and macrophages. In association to other stimuli, the Th1 cytokine IFN-γ induces NO-mediated microbial killing by M1/classically-activated macrophages. By contrast, the Th2 cytokine IL-4 promotes M2/alternatively activated macrophages, which express arginase-1 and shelter infection. Other cytokines, such as RANKL, might also participate in the crosstalk between T cells and macrophages to restrict parasite infection. RANKL and its receptor RANK are known to play an essential role in bone remodeling, by inducing osteoclatogenesis. It has also been shown that RANKL stimulates antigen-presenting cells, such as DCs and macrophages, to enhance T cell responses. Here we investigated how RANKL directly modulates the effector macrophage phenotypes and immunity to L. major parasites. We found that inflammatory peritoneal macrophages from B6 mice express RANK and M2 features, such as CD301 (MGL) and CD206 (mannose receptor). Nonetheless, treatment with RANKL or IFN-γ induced macrophage differentiation into more mature F40/80hi macrophages able to produce IL-12 and TNF-α. In parallel, macrophages treated with RANKL, IFN-γ, or RANKL along with IFN-γ progressively downregulated the expression of the M2 hallmarks MGL, arginase-1, and CCL17. Moreover, a synergism between IFN-γ and RANKL enhanced inducible NO synthase (iNOS) expression and NO production by macrophages. These results are consistent with the idea that RANKL helps IFN-γ to induce a M2-like to M1 phenotype shift. Accordingly, concomitant treatment with RANKL and IFN-γ promoted macrophage-mediated immunity to L. major, by inducing NO and ROS-dependent parasite killing. Furthermore, by cooperating with IFN-γ, endogenous RANKL engages CD4 T-cell help toward L. major-infected macrophages to upregulate M1 and Th1 cytokine responses. Therefore, RANKL, in combination with IFN-γ, is a potential local therapeutic tool to improve immune responses in Leishmaniasis, by skewing M2-like into effector M1 macrophages.

MON-356 Atypical Femur Fracture with Denosumab

Background: Osteoporosis (OP) is a systemic disease that is associated with increased risk for fractures. Anti-resorptive medications (ARM) are an effective modality for treatment and prevention of fractures in OP. Long-term use of ARM like bisphosphonates (BP) is associated with increased risk of atypical femoral fractures (AFF). Denosumab (DM) is monoclonal antibody that targets receptor activator of nuclear factor KB ligand (RANKL). A few cases of AFF with DM have been reported in patients who have previously been on long term BP therapy. We present a case where the patient had only received two zoledronic acid (ZA) infusions, last one three years prior to being initiated on DM and experienced AFF. Case: 73-year-old postmenopausal woman presented to the emergency room with sudden onset pain in the right thigh. Patient was standing and reaching into her closet when she felt a snap in right thigh followed by inability to move the right leg or bear weight on it. X-ray of the right femur showed a displaced femoral shaft fracture with a short transverse fracture line and a spike, without comminution.History was significant for OP for which she received raloxifene for a couple of years followed by ZA in 2013 and 2015 by her primary care. Fracture history was significant for a wrist fracture in 2015, and T12 and L1 fractures in 2017 from coughing while on Medrol dospak for an acute episode of bronchitis. In 2017, bone density showed L1-L4 T score of -2.0, the left total hip T score was -1.8 and left femoral neck T score was -2.5 consistent with OP. Work up for secondary causes of OP was unremarkable. Due to recent T12 and L1 compression fractures, she was recommended DM. She received DM in June 2018 as she was undergoing a dental implant followed by December 2018 and June 2019 and presented with the right femoral fracture in November 2019.Past history was significant for idiopathic pulmonary fibrosis which had been relatively stable without need for long-term steroid therapy. History was negative for diabetes or kidney disease. Menarche was at age 14, menopause at 52 and she did not take any hormone replacement therapy.She underwent surgical fixation with intramedullary rod. Due to concern about ARM associated sub-trochanteric fracture in the right femur, left femur was imaged. She had cortical beaking in the distal third of the left femur, and underwent prophylactic medullary nailing of the left femur as well. Conclusion: AFF are an uncommon complication of ARM used for OP. Not many cases of AFF have been reported with the use of DM and most of the reported cases are associated with prolonged BP therapy. Our case is unusual in that AFF occurred in the absence of prolonged BP therapy and raises concern that a couple of ZA infusions in the past can also increase the risk of AFF. Clinicians need to have a high index of suspicion and may consider doing femur x-rays in patients who have previously been on BP prior to starting DM.

Blockade of RANKL/RANK interaction prevents allergic airway inflammation in a mouse model of asthma

Abstract W are constantly looking for new therapeutic options for asthma treatment. In this study, we investigated whether the signaling pathway of the receptor activator of nuclear factor (NF)-κB (RANK), RANK ligand (RANKL), and its decoy receptor osteoprotegerin (OPG) may be considered as a novel drug target for therapy of allergic asthma. Therefore, we tested the effect of blockade of RANK-L with OPG on the development of ovalbumin (OVA)-induced airway allergic inflammation (AAI) and accompanying immune response. The absolute counts of CD11chighCD11b+CD103− (CD11b+) dendritic cells (DC), ST2+Foxp3−CD4+ (Th2) cells and BrdU+(i.e., proliferating)CD4+ T cells were determined in the mediastinal lymph nodes (MLNs) and lungs of untreated non-immunized mice, untreated OVA-immunized mice and OPG-treated OVA-immunized mice. Immunization with OVA induced a significant increase in the mean scores of lung histologic lesions and administration of OPG completely prevented this effect. The absolute counts of CD11b+ DC, Th2 cells and BrdU+CD4+ T cells were increased in the MLNs and lungs of untreated OVA-immunized mice. Treatment with OPG attenuated, but did not abolish, the OVA-induced increase in the count of CD11b+ DC in the MLNs. In turn, administration of this agent prevented the OVA-induced increase in the count of Th2 cells and BrdU+CD4+ T cells in the MLNs and lungs. In conclusion, blockade of RANK/RANKL interaction prevents OVA-induced AAI and this effect is mediated through inhibition the allergen-induced clonal expansion of CD4+ T cells in the MLNs. Clinical implication: the local inhibition of RANK/RANK-L interaction within the respiratory system can be considered as a novel therapeutic strategy in treatment of allergic asthma.

MicroRNA-143-3p regulates odontogenic differentiation of human dental pulp stem cells through regulation of the osteoprotegerin-RANK ligand pathway by targeting RANK.

What is the central question of this study? What is the role of miR-143-3p during human dental pulp stem cell (hDPSC) differentiation. What is the main finding and its importance? miR-143-3p negatively regulates receptor activator of nuclear factor-κB (RANK). RANK ligand (RANKL) binds to RANK and stimulates the development of osteoclasts. Osteoprotegerin (OPG) inhibits the interaction between RANK and RANKL. The OPG-RANKL signalling pathway regulates odontogenic differentiation of hDPSCs. Human dental pulp stem cells (hDPSCs) are capable of differentiating into odontoblast-like cells, which secrete reparative dentin after injury, in which the role of microRNA-143-3p (miR-143-3p) has been identified. Therefore, we investigated the mechanism by which miR-143-3p influences odontoblastic differentiation of hDPSCs. The relationship between miR-143-3p and receptor activator of nuclear factor-κB (RANK) was initially identified by bioinformatics prediction and further verified by dual luciferase reporter gene assay. Gain- and loss-of-function analysis with miR-143-3p mimic and miR-143-3p inhibitor was subsequently conducted. Dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), alkaline phosphatase (ALP), osteocalcin (OCN) and osteopontin (OPN) mRNA levels were then evaluated by RT-qPCR. Osteoprotegerin (OPG), RANK ligand (RANKL), nuclear factor-κB (NF-κB) p65 protein levels and the extent of NF-κB p65 phosphorylation were examined by western blot analysis. Alizarin red staining was performed to assess the mineralization of hDPSCs. Cell apoptosis and cell cycle distribution were determined using flow cytometry. During odontoblastic differentiation of hDPSC, miR-143-3p had high expression, but RANK expression was low. miR-143-3p was found to target RANK, and its inhibition enhanced mineralization and hDPSC apoptosis, while blocking cell cycle entry. At the same time, miR-143-3p inhibition elevated the extent of NF-κB p65 phosphorylation, as well as the expression of RANK, RANKL, DSPP, BSP, ALP, OCN and OPN, while decreasing the OPG level. Silencing RANK had opposite effects on these markers. miR-143-3p regulates odontoblastic differentiation of hDPSCs via the OPG-RANKL pathway that targets RANK. The elucidation of the mechanisms of odontogenic differentiation of hDPSCs may contribute to the development of effective dental pulp repair therapies for the clinical setting.

Green Tea Catechin (-)-Epigallocatechin-3-Gallate (EGCG) Facilitates Fracture Healing.

Green tea drinking can ameliorate postmenopausal osteoporosis by increasing the bone mineral density. (-)-Epigallocatechin-3-gallate (EGCG), the abundant and active compound of tea catechin, was proven to be able to reduce bone loss and ameliorate microarchitecture in female ovariectomized rats. EGCG can also enhance the osteogenic differentiation of murine bone marrow mesenchymal stem cells and inhibit the osteoclastogenesis in RAW264.7 cells by modulation of the receptor activator of nuclear factor-kB (RANK)/RANK ligand (RANKL)/osteoprotegrin (OPG) (RANK/RANKL/OPG) pathway. Our previous study also found that EGCG can promote bone defect healing in the distal femur partially via bone morphogenetic protein-2 (BMP-2). Considering the osteoinduction property of BMP-2, we hypothesized that EGCG could accelerate the bone healing process with an increased expression of BMP-2. In this manuscript, we studied whether the local use of EGCG can facilitate tibial fracture healing. Fifty-six 4-month-old rats were randomly assigned to two groups after being weight-matched: a control group with vehicle treatment (Ctrl) and a study group with 10 µmol/L, 40 µL, EGCG treatment (EGCG). Two days after the operation, the rats were treated daily with EGCG or vehicle by percutaneous local injection for 2 weeks. The application of EGCG enhanced callus formation by increasing the bone volume and subsequently improved the mechanical properties of the tibial bone, including the maximal load, break load, stiffness, and Young’s modulus. The results of the histology and BMP-2 immunohistochemistry staining showed that EGCG treatment accelerated the bone matrix formation and produced a stronger expression of BMP-2. Taken together, this study for the first time demonstrated that local treatment of EGCG can accelerate the fracture healing process at least partly via BMP-2.

Osteoblasts Suppress Bone Resorption Via Production of Osteoprotegerin

Osteoprotegerin (OPG) inhibits the ability of receptor activator of NFkB ligand (RANKL) to stimulate the differentiation, activity, and survival of bone resorbing osteoclasts. Genetic studies in mice show that osteocytes are an important source of RANKL, but the cellular sources of OPG are unclear. We used conditional deletion of Tnfrsf11b, which encodes OPG, from different cell populations to identify functionally relevant sources of OPG in mice. Deletion from B lymphocytes and osteocytes, two cell types commonly thought to supply OPG, had little or no impact on bone mass. In contrast, deletion of Tnfrsf11b from osteoblasts increased bone resorption and reduced bone mass to an extent similar to germline deletion, demonstrating that osteoblasts are an essential source of OPG. These results suggest that, in addition to producing new bone matrix, osteoblasts also play an active role in terminating the resorption phase of the bone remodeling cycle by suppressing RANKL activity.

Juvenile Paget's Disease From Heterozygous Mutation of SP7 Encoding Osterix (Specificity Protein 7, Transcription Factor SP7).

Juvenile Paget's disease (JPD) became in 1974 the commonly used name for ultra-rare heritable occurrences of rapid bone remodeling throughout of the skeleton that present in infancy or early childhood as fractures and deformity hallmarked biochemically by marked elevation of serum alkaline phosphatase (ALP) activity (hyperphosphatasemia). Untreated, JPD can kill during childhood or young adult life. In 2002, we reported that homozygous deletion of the gene called tumor necrosis factor receptor superfamily, member 11B (TNFRSF11B) encoding osteoprotegerin (OPG) explained JPD in Navajos. Soon after, other bi-allelic loss-of-function TNFRSF11B defects were identified in JPD worldwide. OPG inhibits osteoclastogenesis and osteoclast activity by decoying receptor activator of nuclear factor κ-B (RANK) ligand (RANKL) away from its receptor RANK. Then, in 2014, we reported JPD in a Bolivian girl caused by a heterozygous activating duplication within TNFRSF11A encoding RANK. Herein, we identify mutation of a third gene underlying JPD. An infant girl began atraumatic fracturing of her lower extremity long-bones. Skull deformity and mild hearing loss followed. Our single investigation of the patient, when she was 15 years-of-age, showed generalized osteosclerosis and hyperostosis. DXA revealed a Z-score of +5.1 at her lumbar spine and T-score of +3.3 at her non-dominant wrist. Biochemical studies were consistent with positive mineral balance and several markers of bone turnover were elevated and included striking hyperphosphatasemia. Iliac crest histopathology was consistent with rapid skeletal remodeling. Measles virus transcripts, common in classic Paget's disease of bone, were not detected in circulating mononuclear cells. Then, reportedly, she responded to several months of alendronate therapy with less skeletal pain and correction of hyperphosphatasemia but had been lost to our follow-up. After we detected no defect in TNFRSF11A or B, trio exome sequencing revealed a de novo heterozygous missense mutation (c.926C>G; p.S309W) within SP7 encoding the osteoblast transcription factor osterix (specificity protein 7, transcription factor SP7). Thus, mutation of SP7 represents a third genetic cause of JPD.

Comparison of RANKL and osteoprotegerin levels in the gingival crevicular fluid of young cigarette- and waterpipe-smokers and individuals using electronic nicotine delivery systems

The aim of the present observational case-control study was to compare the levels of Receptor activator of NF-kappa B ligand (RANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) of cigarette- and waterpipe-smokers and electronic-nicotine-delivery-systems (ENDS)-users. Demographic data was collected using a questionnaire. Clinical periodontal parameters (plaque index [PI], bleeding on probing [BOP], probing depth [PD] and clinical attachment loss [CAL]) were measured; and GCF samples were collected from the deepest periodontal pocket of the mandibular right first molar. The GCF volume was determined and levels of RANKL and OPG were determined. Group comparisons were performed and P < 0.05 was considered statistically significant. One hundred and twenty male individuals (30 cigarette-smokers, 30 waterpipe users, 30 ENDS-users and 30 non-smokers) were included. Scores of PI (P < 0.01) and PD (P < 0.01) were significantly higher among cigarette- and waterpipe smokers, and ENDS-users than non-smokers. The GCF volume was significantly higher among cigarette- (0.92 ± 0.05 μl) (P < 0.01) and waterpipe-smokers (0.66 ± 0.08 μl) (P < 0.001) and ENDS-users (0.62 ± 0.03 μl) (P < 0.01) than non-smokers (0.21 ± 0.007 μl). The GCF RANKL levels were significantly higher among cigarette- (14.9 ± 8.2 pg/ml) (P < 0.001) and waterpipe-smokers (12.6 ± 8.8 pg/ml) (P < 0.01) and ENDS-users (11.5 ± 8.4 pg/ml) (P < 0.01) than non-smokers (3.5 ± 0.7 pg/ml). The GCF OPG levels were significantly higher among cigarette- (95.9 ± 7.2 pg/ml) (P < 0.001) and waterpipe-smokers (86.6 ± 5.8 pg/ml) (P < 0.01) and ENDS-users (77.5 ± 3.4 pg/ml) (P < 0.05) than non-smokers (21.5 ± 10.7 pg/ml). There was no significant difference in GCF RANKL and OPG levels among cigarette- and waterpipe smokers, ENDS users. Cigarette- and waterpipe smoking and ENDS usage is associated with an increased expression of RANKL and OPG in the GCF.

Osteoprotegerin: Relationship to Breast Cancer Risk and Prognosis.

Osteoprotegerin (OPG) is a secreted member of the Tumor Necrosis Factor (TNF) receptor superfamily (TNFRSF11B), that was first characterized and named for its protective role in bone remodeling. In this context, OPG binds to another TNF superfamily member Receptor Activator of NF-kappaB Ligand (RANKL; TNFSF11) and blocks interaction with RANK (TNFRSF11A), preventing RANKL/RANK stimulation of osteoclast maturation, and bone breakdown. Further studies revealed that OPG protein is also expressed by tumor cells and led to investigation of the role of OPG in tumor biology. An increasing body of data has demonstrated that OPG modulates breast tumor behavior. Initially, research was focused on OPG in the bone microenvironment as a potential inhibitor of RANKL-driven osteolysis. More recently, attention has shifted to include OPG expression and interactions in the primary breast tumor independent of RANKL. In the primary tumor, OPG may interact with another TNF superfamily member, TNF-Related Apoptosis Inducing Ligand (TRAIL; TNFSF10) to prevent apoptosis induction. Additional interest in OPG in breast cancer has been stimulated by the tumor-promoting role of its binding partner RANKL in association with BRCA1 gene mutations. We and others have previously summarized the functional studies on OPG and breast cancer (1, 2). After basic research studies on the in vitro role for OPG (and RANKL) in breast cancer, the field now expands to assess the in vivo role for OPG by examining the correlation between OPG expression and breast cancer risk or patient prognosis. However, the data reported so far is conflicting, since OPG expression appears linked to both good and poor patient survival. In the current review we will summarize these studies. Our goal is to provide stimulus for further research to bridge the basic research findings and clinical data regarding OPG in breast cancer.

Effects of the Bone/Bone Marrow Microenvironments on Prostate Cancer Cells and CD59 Expression.

Objective To evaluate the effects of human bone marrow mesenchymal stem cells (hBMSCs) and osteoblasts (hFOB1.19) on PC3 prostate cancer cells. Methods To simulate the in vivo interaction between the bone/bone marrow microenvironments and prostate cancer cells, we established cocultures of PC3 cells with hBMSC or hFOB1.19 cells and evaluated their effects on the proliferation, cell cycle distribution, cell migration, and invasion of PC3 cells. Quantitative reverse transcription polymerase chain reaction was used to detect CD59 mRNA expression in PC3 cells. The expression of receptor activator of nuclear factor- (NF-) κB (RANK), RANK ligand (RANKL), osteoprotegerin (OPG), CD59, NF-κB (p50 subunit), and cyclin D1 in PC3 cells was analyzed by immunofluorescence and western blotting. Results hBMSCs and hFOB1.19 cells enhanced the proliferation, migration, and invasion of PC3 cells; increased the proportion of PC3 cells in the S and G2/M phases of the cell cycle; and upregulated RANK, RANKL, OPG, CD59, cyclin D1, and NF-κB (p50 subunit) expression by PC3 cells. The RANKL inhibitor, scutellarin, inhibited these effects in PC3-hFOB1.19 cocultures. Conclusion hBMSCs and hFOB1.19 cells modulate the phenotype of PC3 prostate cancer cells and the expression of CD59 by activating the RANK/RANKL/OPG signaling pathway.

DeepBindPoc: a deep learning method to rank ligand binding pockets using molecular vector representation.

Accurate identification of ligand-binding pockets in a protein is important for structure-based drug design. In recent years, several deep learning models were developed to learn important physical–chemical and spatial information to predict ligand-binding pockets in a protein. However, ranking the native ligand binding pockets from a pool of predicted pockets is still a hard task for computational molecular biologists using a single web-based tool. Hence, we believe, by using closer to real application data set as training and by providing ligand information, an enhanced model to identify accurate pockets can be obtained. In this article, we propose a new deep learning method called DeepBindPoc for identifying and ranking ligand-binding pockets in proteins. The model is built by using information about the binding pocket and associated ligand. We take advantage of the mol2vec tool to represent both the given ligand and pocket as vectors to construct a densely fully connected layer model. During the training, important features for pocket-ligand binding are automatically extracted and high-level information is preserved appropriately. DeepBindPoc demonstrated a strong complementary advantage for the detection of native-like pockets when combined with traditional popular methods, such as fpocket and P2Rank. The proposed method is extensively tested and validated with standard procedures on multiple datasets, including a dataset with G-protein Coupled receptors. The systematic testing and validation of our method suggest that DeepBindPoc is a valuable tool to rank near-native pockets for theoretically modeled protein with unknown experimental active site but have known ligand. The DeepBindPoc model described in this article is available at GitHub (https://github.com/haiping1010/DeepBindPoc) and the webserver is available at (http://cbblab.siat.ac.cn/DeepBindPoc/index.php).

The Role of FSH in Osteoporosis and Subsequent Oral Disease

Osteoporosis is an age‐related chronic disease in which osteoclasts degrade minerals of the bone faster than osteoblasts can replace them. In addition to increased risk of fracture, osteoporosis patients experience oral, dental and prosthodontic complications due to degradation of the alveolar and jaw bone. Elderly women are disproportionately impacted by this disease. One potential culprit for the gender‐based disparity is the increased levels of follicle stimulating hormone (FSH) during menopause. An isoform of the FSH receptor can be found on osteoclasts; when FSH binds to this receptor, osteoclast activity and differentiation are increased. Murine monocytes were differentiated into osteoclasts using RANK ligand, and FSH dependent signaling was measured through western blotting. Protein phosphorylation was detected in response to FSH in osteoclasts. A better understanding of the osteoclast FSH receptor could allow for pharmaceutical intervention to interrupt the pathway. Negative allosteric modulators (NAMs) that inhibit FSH signalling on granulosa cells could be used for inhibiting FSH signalling on osteoclasts.

Isorhamnetin 3-O-neohesperidoside promotes the resorption of crown-covered bone during tooth eruption by osteoclastogenesis

Delayed resorption of crown-covered bone is a critical cause of delayed tooth eruption. Traditional herbal medicines may be good auxiliary treatments to promote the resorption of crown-covered bone. This study was carried out to analyse the effect of isorhamnetin 3-O-neohesperidoside on receptor activator of nuclear factor-kB ligand (RANKL)-induced osteoclastogenesis in vitro and resorption of the crown-covered bone of the lower first molars in mice in vivo. Isorhamnetin 3-O-neohesperidoside promoted osteoclastogenesis and the bone resorption of mouse bone marrow macrophages (BMMs) and upregulated mRNA expression of the osteoclast-specific genes cathepsin K (CTSK), vacuolar-type H + -ATPase d2(V-ATPase d2), tartrate resistant acid phosphatase (TRAP) and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). NFATc1, p38 and AKT signalling was obviously activated by isorhamnetin 3-O-neohesperidoside in osteoclastogenesis. Isorhamnetin 3-O-neohesperidoside aggravated resorption of crown-covered bone in vivo. In brief, isorhamnetin 3-O-neohesperidoside might be a candidate adjuvant therapy for delayed intraosseous eruption.