Multiple myeloma is an incurable malignant disease characterized by proliferation of clonal plasma cells in the bone marrow.About 90% of the patients with multiple myeloma develop myeloma bone disease(MBD),which seriously affects the quality of life and prognosis of the patients.Traditional therapies for MBD include bisphosphonates,radiotherapy,and surgery.The recent studies have confirmed that the receptor activator of nuclear factor κB ligand (RANKL)-receptor activator of nuclear factor κB(RANK) signaling pathway plays a key role in MBD,providing a new therapeutic target for MBD.This review summarized the role of RANKL-RANK signaling pathway in the pathogenesis of MBD and the advance in the targeted therapy.
Bone Diseases/metabolism* ; Humans ; Ligands ; Multiple Myeloma/metabolism* ; NF-kappa B/metabolism* ; Quality of Life ; RANK Ligand/metabolism* ; Receptor Activator of Nuclear Factor-kappa B ; Signal Transduction

Bone invasion by oral cancer is a common clinical problem, which affects the choice of treatment and predicts a poor prognosis. Unfortunately, the molecular mechanism of this phenomenon has not been fully elucidated. Current studies have revealed that oral cancer cells modulate the formation and function of osteoclasts through the expression of a series of signal molecules. Many signal pathways are involved in this process, of which receptor activator of nuclear factor-κB ligand/receptor activator of nuclear factor-κB/osteoprotegerin signaling pathway attracted much attention. In this review, we introduce recent progress in molecular mechanisms of bone invasion by oral cancer.
Bone Resorption ; Bone and Bones ; Humans ; Mouth Neoplasms ; Osteoclasts ; Osteoprotegerin ; RANK Ligand ; Receptor Activator of Nuclear Factor-kappa B

OBJECTIVE: To explore the effect of advanced glycation end products (AGEs) on osteoclasts at different stages of differentiation. METHODS: Raw264.7 cells cultured were induced for osteoclastogenesis using RANKL, and the stages of differentiation of the osteoclasts were determined with TRAP staining. The cells were then randomly divided into control group, early-stage AGEs intervention group and late-stage AGEs intervention group. The viability of the cells after AGEs treatment was assessed using CCK-8 method. The cells were examined after the induction for osteoclastogenesis using TRAP staining, and the expression levels of RANK, NFATC-1, TRAF-6, TRAP and CTSK mRNAs were tested with RT-PCR; the expressions of CTSK and RANK proteins were detected using Western boltting. RESULTS: We defined the initial 3 days of induction as the early stage of differentiation and the time beyond 3 days as the late stage of differentiation of Raw264.7 cells. Intervention with AGEs at 100 mg/L produced no significant effects on the viability of the cells, but AGEs suppressed the cell proliferation at a concentration exceeding 100 mg/L. The number of osteolasts in the early- and late-stage intervention groups was greater than that in the control group, but the cell count differed significantly only between the early-stage intervention group and control group ( < 0.05). The gene expressions of RANK, NFATC-1, TRAF-6, TRAP and CTSK all increased after the application of AGEs in both the early and late stages of differentiation, but the changes were significant only in the early-stage intervention group ( < 0.05). The changes in CTSK and RANK protein expressions were consistent with their mRNA expressions. CONCLUSIONS AGEs can affect the differentiation of osteoclasts differently when applied at different stages, and intervention with AGEs at the early stage produces stronger effect to promote osteoclast differentiation than its application at a late stage.
Animals ; Bone Resorption ; Cell Differentiation ; Mice ; Osteoclasts ; RANK Ligand ; RAW 264.7 Cells ; Receptor Activator of Nuclear Factor-kappa B

OBJECTIVES: Root resorption is an unexpected complication after replantation procedures. Combining anti-osteoclastic medicaments with retrograde root filling materials may avert this resorptive activity. The purpose of this study was to assess effects of a cathepsin K inhibitor with calcium silicate-based cements on osteoclastic activity. METHODS: MC3T3-E1 cells were cultured for biocompatibility analyses. RAW 264.7 cells were cultured in the presence of the receptor activator of nuclear factor-kappa B and lipopolysaccharide, followed by treatment with Biodentine (BIOD) or ProRoot MTA with or without medicaments (Odanacatib [ODN], a cathepsin inhibitor and alendronate, a bisphosphonate). After drug treatment, the cell counting kit-8 assay and Alizarin red staining were performed to evaluate biocompatibility in MC3T3-E1 cells. Reverse-transcription polymerase chain reaction, tartrate-resistant acid phosphatase (TRAP) staining and enzyme-linked immunosorbent assays were performed in RAW 264.7 cells to determine the expression levels of inflammatory cytokines, interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2). Data were analyzed by one-way analysis of variance and Tukey's post hoc test (p < 0.05). RESULTS: Biocompatibility results showed that there were no significant differences among any of the groups. RAW 264.7 cells treated with BIOD and ODN showed the lowest levels of TNF-α and PGE2. Treatments with BIOD + ODN were more potent suppressors of inflammatory cytokine expression (p < 0.05). CONCLUSION: The cathepsin K inhibitor with calcium silicate-based cement inhibits osteoclastic activity. This may have clinical application in preventing inflammatory root resorption in replanted teeth.
Acid Phosphatase ; Alendronate ; Calcium ; Cathepsin K ; Cathepsins ; Cell Count ; Cytokines ; Dinoprostone ; Enzyme-Linked Immunosorbent Assay ; Interleukin-6 ; Interleukins ; Miners ; Necrosis ; Osteoblasts ; Osteoclasts ; Pemetrexed ; Polymerase Chain Reaction ; RAW 264.7 Cells ; Receptor Activator of Nuclear Factor-kappa B ; Replantation ; Root Resorption ; Tooth

BACKGROUND: Tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame-retardants, is a representative persistent organic pollutants group. Studies on TBBPA toxicity have been conducted using various target cells; however, few studies have investigated TBBPA toxicity in bone cells. Therefore, this study investigated the in vitro effects of TBBPA on osteoclasts, a cell type involved in bone metabolism. METHODS: RAW264.7 cells were cultured in medium containing 50 ng/mL receptor activator of nuclear factor kappa B ligand (RANKL) and varying concentrations of TBBPA. To evaluate the effects of TBBPA on the differentiation and function of osteoclasts, osteoclast-specific gene expression, tartrate-resistant acid phosphatase (TRAP) activity, bone resorbing activity, mitochondrial membrane potential (MMP) and mitochondrial superoxide were measured. RESULTS: The presence of 20 μM TBBPA significantly increased TRAP activity in RANKL-stimulated RAW264.7 cells, the bone resorbing activity of osteoclasts, and the gene expression of Akt2, nuclear factor of activated T-cells cytoplasmic 1, and chloride channel voltage-sensitive 7. However, TBBPA treatment caused no change in the expression of carbonic anhydrase II, cathepsin K, osteopetrosis-associated transmembrane protein 1, Src, extracellular signal-related kinase, GAB2, c-Fos, or matrix metalloproteinase 9. Furthermore, 20 μM TBBPA caused a significant decrease in MMP and a significant increase in mitochondrial superoxide production. CONCLUSION: This study suggests that TBBPA promotes osteoclast differentiation and activity. The mechanism of TBBPA-stimulated osteoclastogenesis might include increased expression of several genes involved in osteoclast differentiation and reactive oxygen species production.
Acid Phosphatase ; Carbonic Anhydrase II ; Cathepsin K ; Chloride Channels ; Cytoplasm ; Gene Expression ; In Vitro Techniques ; Matrix Metalloproteinase 9 ; Membrane Potential, Mitochondrial ; Metabolism ; Osteoclasts ; Phosphotransferases ; RANK Ligand ; Reactive Oxygen Species ; Receptor Activator of Nuclear Factor-kappa B ; Superoxides ; T-Lymphocytes

PURPOSE: The purpose of this study was to evaluate the optimal diabetes duration for bone regeneration experiments in an alloxan monohydrate (ALX)–induced diabetic rabbit calvarial defect model by evaluating the association between diabetes duration and bone healing capacity. METHODS: Twenty-four New Zealand white rabbits were used. Twenty-two rabbits were injected with 100 mg/kg of ALX to induce experimental diabetes. These rabbits were divided into 4 groups, including a control group and groups with diabetes durations of 1 week (group 1), 2 weeks (group 2), and 4 weeks (group 3). Calvarial defects were created at 1, 2, and 4 weeks after ALX injection and in the control rabbits. Cone-beam computed tomography (CBCT) scanning was performed on the day of surgery and at 2 and 4 weeks after surgery. The rabbits were sacrificed 4 weeks after surgery, followed by histological and immunofluorescence analysis. RESULTS: The diabetic state of all diabetic rabbits was well-maintained throughout the experiment. Reconstructed 3-dimensional CBCT imaging showed more rapid and prominent bone regeneration in the control group than in the experimental groups. Histological staining showed notable bone regeneration in the control group, in contrast to scarce bone formation in the experimental groups. The appearance and immunoreactivity of receptor activator of nuclear factor-kappa B and osteoprotegerin did not show notable differences among the groups. CONCLUSION: ALX administration at 100 mg/kg successfully induced experimental diabetes in rabbits. The effect of diabetes on bone healing was evident when the interval between diabetes induction and the intervention was ≥1 week.
Alloxan ; Animals ; Bone Regeneration ; Cone-Beam Computed Tomography ; Diabetes Mellitus, Experimental ; Fluorescent Antibody Technique ; Osteogenesis ; Osteoprotegerin ; Rabbits ; Receptor Activator of Nuclear Factor-kappa B

<b>OBJECTIVEb>To establish osteoblast-osteoclast cell co-culture system in a Transwell chamber, and detect cell viability of osteoblasts and osteoclasts in system.

<b>METHODSb>Osteoblast MC3T3-E1 and mouse monocytes RAW264.7 were cultivated in vitro. RANKL-induced mouse RAW264.7 monocytes differentiated into mature osteoclasts, osteoblast-osteoclast cell co-culture system was established in Transwell chamber. Cell activity of osteoblasts and osteoclasts were detected by CCK-8 experimenting, Alizarin Red staining, TRAP staining. The expression of OPG, ALP, RANKL, TGF-b1 gene and RANKL protein in osteoblast MC3T3-E1 were detected by PCR, Western-Blot methods. Also, the expression of RANK, NF-&kappa;B in gene and protein level in osteoclast were measured through the same method respectively.

<b>RESULTSb>The co-culture system of Mouse MC3T3-E1 cells and RAW264.7 cell were established in Transwell chamber. Co-culture system affected cell division activities of osteoblasts and osteoclasts. Differentiation of osteoblasts were increased, while differentiation of osteoclast division were slight decreased under microscope observation. OPG (0.65±0.08) and ALP (0.16±0.01) gene expression of co-culture system were less than single culture OPG(1.00±0.08) and ALP (1.01±0.16); TGF-b1(4.42±0.21) and RANKL(4.12±1.04) of osteoblasts in co-culture system were higher than TGF-b1(1.00±0.10) and RANKL(1.00±0.09) under single culture. However, gene expression of RANK(0.63±0.06) and NF-&kappa;B(0.64±0.08) in co-culture system were decreased than RANK(1.00±0.08) and NF-&kappa;B(1.00±0.09), in single culture, and had significant differences. Similarly, protein expression of OPG(0.43±0.05) and NF-&kappa;B(0.59±0.05) of co-culture system were less than OPG(0.84±0.06) and NF-&kappa;B(1.13±0.03) of single culture. While RANKL protein expression (0.54±0.03)of co-culture system was more than single culture RANKL(0.31±0.03), and had statistically differences, which was in agreement of the trend of gene expression change.

<b>CONCLUSIONSb>Co-culture system of mouse MC3T3-E1 cells and RAW264.7 cell was viable in Transwell chamber, and the activity of osteoblasts is higher than osteoclasts in co-culture system.

3T3 Cells ; Animals ; Cell Differentiation ; Coculture Techniques ; Mice ; NF-kappa B ; metabolism ; Osteoblasts ; cytology ; Osteoclasts ; cytology ; Osteoprotegerin ; metabolism ; RANK Ligand ; metabolism ; RAW 264.7 Cells ; Receptor Activator of Nuclear Factor-kappa B ; metabolism ; Transforming Growth Factor beta1 ; metabolism

<b>OBJECTIVEb>This work aims to examine the effects of paeonol treatment on the ability of bone marrow-derived macrophage (BMM) to excrete inflammatory factors and to differentiate into osteoclasts upon induction with Porphyromonas gingivalis (P. gingivalis). This work also aims to investigate the underlying mechanisms of these abilities.

<b>METHODSb>BMM culture was treated with different paeonol concentrations at for 1 h and then stimulated with P. gingivalis for 24 h before programmed death-ligand 1 (PD-L1) was quantified with flow cytometry. Tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA). The BMM culture was treated with the receptor activator for nuclear factor-&kappa;B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF), and then with paeonol for 1 h prior to induction with P. gingivalis. Then, osteoclast formation was assessed using tartrate resistant acid phosphatase (TRAP) staining. The osteoclast-related proteins TRAP and receptor activator of nuclear factor-&kappa;B (RANK) were quantified by Western blotting.

<b>RESULTSb>Paeonol was nontoxic to BMM within a range of 10-50 μmol·L⁻¹. Flow cytometry showed that paeonol inhibited PD-L1 expression in P. gingivalis-induced BMM in a dose-dependent manner. ELISA indicated that paeonol dose-dependently inhibited the excretion of TNF-α, IL-1β, and IL-6 by P. gingivalis-induced BMM (P<0.01). TRAP staining revealed that paenol treatment inhibited the differentiation of P. gingivalis-induced BMM into osteoclasts. Western blot results suggested that paeonol decreased the expression of TRAP and RANK in BMM.

<b>CONCLUSIONSb>Paeonol dose-dependently inhibited the excretion of the inflammatory factors TNF-α, IL-1β, and IL-6 by P. gingivalis-induced BMM in a dose-dependent manner. Moreover, paenol treatment prevented the differentiation of P. gingivalis-induced BMM differentiation into osteoclasts.
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Acetophenones ; pharmacology ; Acid Phosphatase ; Animals ; Carrier Proteins ; Cell Differentiation ; Interleukin-1beta ; Interleukin-6 ; Isoenzymes ; Macrophage Colony-Stimulating Factor ; Macrophages ; Membrane Glycoproteins ; Mice ; Osteoclasts ; Porphyromonas gingivalis ; RANK Ligand ; Receptor Activator of Nuclear Factor-kappa B ; Tumor Necrosis Factor-alpha

Preterm birth defined as birth between 20-37 weeks age of gestation, poses major concerns as it causes serious health problems. Across 184 countries, the rate of preterm birth ranges from 5% to 18% of babies born and the Philippines ranks 8th out of 184 countries for the number of babies born prematurely, and ranks 17th for the total number of deaths due to complications from preterm birth. Management of incompetent cervix as one of the causes of preterm birth is cerclage. However, pessary insertion is an alternative especially in cases where cerclage may not be employed. To date, there have been no local published reports on effectiveness of pessary in prevention of preterm birth. Hence this study aims to report on cases supporting the use of pessary in preterm birth. This is a case series of three patients with short functional cervical lengths (<2.5 cm) seen in ultrasound, managed with pessary insertion showing its effectiveness in prolonging pregnancy. In conclusion, pessary is an affordable and safe alternative management of preterm birth which may be employed in our setting. Future clinical trials may be helpful in strengthening this evidence.

Human ; Female ; Adult ; Pregnancy ; Uterine Cervical Incompetence ; Pessaries ; Premature Birth ; Parturition ; Pregnancy, Prolonged ; Tnfrsf11a Protein, Human ; Receptor Activator Of Nuclear Factor-kappa B

Preterm birth defined as birth between 20-37 weeks age of gestation, poses major concerns as it causes serious health problems. Across 184 countries, the rate of preterm birth ranges from 5% to 18% of babies born and the Philippines ranks 8th out of 184 countries for the number of babies born prematurely, and ranks 17th for the total number of deaths due to complications from preterm birth. Management of incompetent cervix as one of the causes of preterm birth is cerclage. However, pessary insertion is an alternative especially in cases where cerclage may not be employed. To date, there have been no local published reports on effectiveness of pessary in prevention of preterm birth. Hence this study aims to report on cases supporting the use of pessary in preterm birth. This is a case series of three patients with short functional cervical lengths (<2.5 cm) seen in ultrasound, managed with pessary insertion showing its effectiveness in prolonging pregnancy. In conclusion, pessary is an affordable and safe alternative management of preterm birth which may be employed in our setting. Future clinical trials may be helpful in strengthening this evidence.

Human ; Female ; Adult ; Pregnancy ; Uterine Cervical Incompetence ; Pessaries ; Premature Birth ; Parturition ; Pregnancy, Prolonged ; Tnfrsf11a Protein, Human ; Receptor Activator Of Nuclear Factor-kappa B