Diferencia en la expresión del ligando de receptor activador para el factor nuclear K B, en tejido tumoral frente a la infección por diferentes patógenos periodontales / Difference in receptor activator of nuclear factor K B expression in tumoral tissue by different periodontal pathogens

La enfermedad periodontal es una de las principales causas de pérdida dentaria. Clínicamente, esta patología, mediada por la desregulación del sistema inmune producto de una disbiosis ocurrida en el surco gingival, inicia con la inflamación de la encía y evoluciona con el daño irreversible de los tejidos que rodean el diente. El hueso alveolar es uno de los tejidos afectados esta patología, esto debido a la activación de osteoclastos por la sobreexpresión de la proteína RANKL en el huésped. El propósito de este trabajo es determinar el nivel de sobreexpresión de RANKL, en un modelo de células tumorales U2OS, frente a la infección con Porphyromonas gingivalis y Prevotella intermedia. Para identificar el nivel de RANKL, se definieron cuatro grupos: Un grupo control, no tratado; Grupo PG, tratado con P. gingivalis; Grupo PI, tratado con P. Intermedia; y un grupo PG+PI, tratado con ambas bacterias. El nivel relativo de la proteína RANKL fue determinado en el sobrenadante y en los extractos celulares de manera independiente, mediante la técnica Western blot. En sobrenadantes, el grupo PG mostró mayores niveles de RANKL comparados con PI (p < 0,05). En extractos celulares los niveles fueron mayores en el grupo PG+PI (p < 0,05). El grupo PI mostró los niveles más bajos de RANKL. La infección polimicrobiana resulta en una mayor expresión de RANKL en células tumorales U2OS, mientras que frente a la infección P. gingivalis, se observó mayor cantidad de RANKL soluble.

SUMMARY: Periodontal disease is one of the main causes of tooth loss. Clinically, this pathology, mediated by the deregulation of the immune system due to a dysbiosis occurred in the gingival sulcus, begins with the inflammation of the gum and evolves with the irreversible damage of the tissues that surround the tooth. Alveolar bone is one of the most affected tissues by this disease, due to the activation of osteoclasts by the upregulation of RANKL in the host. The aim of this study is to determine the increase of RANKL, in a U2OS tumor cells model, inoculated with Porphyromonas gingivalis and Prevotella intermedia. To identify the level of RANKL, four groups were defined: A control group, not treated; PG group, treated with P.gingivalis; PI group, treated with P. intermedia; and a PG+PI group, treated with both bacteria. The relative level of RANKL was determined in the supernatant and cell extracts independently, using the Western blot technique. In supernatants, the PG group showed higher RANKL levels compared to PI (p < 0.05). In cell extracts the levels were higher in the PG+PI group (p < 0.05.). The PI group showed the lowest levels of RANKL.Polymicrobial infection results in a greater expression of of soluble RANKL was observed.

Traditional Chinese Medicine in Prevention and Treatment of Osteonecrosis of Femoral Head Based on OPG/RANK/RANKL Signaling Pathway： A Review / 中国实验方剂学杂志

Osteonecrosis of the femoral head （ONFH） is a painful and debilitating disease caused by impaired blood supply to the femoral head and cellular and tissue degeneration， leading to gradual destruction of the bone structure and progressive collapse of the femoral head. The main pathological mechanism of ONFH is the disruption of the balance between bone absorption and the reconstruction of new bone， resulting from microcirculation damage and decreased cellular tissue ability. This imbalance leads to biomechanical changes and accelerates the pathological progression of ONFH. In the early stages， clinical manifestations may not be obvious， mainly presenting as pain or discomfort in the hip or groin area， which can be relieved after rest. In the later stage of the disease， pain intensifies， and limb shortening， lower limb weakness， difficulty walking， or limping may occur. Currently， western medicine commonly uses osteogenic agents， anticoagulants， and artificial joint replacement for treatment， but there are also many issues such as prosthesis loosening and infection. Research has shown that traditional Chinese medicine （TCM） treatment of ONFH takes a holistic approach and employs multi-functional， multi-target， and multi-system Chinese medicine therapies， ensuring the safety and effectiveness of the treatment. The osteoprotegerin （OPG）/receptor activator of nuclear factor-κB （RANK）/RANK ligand （RANKL） signaling pathway plays a crucial role in maintaining the dynamic balance of bone remodeling. TCM treatments utilize this pathway to promote apoptosis of osteoclasts， reduce bone resorption， and accelerate bone formation， thereby playing an important role in the prevention and treatment of ONFH. This paper reviewed the role of OPG/RANK/RANKL signaling pathway and related cytokine expression in ONFH by reviewing relevant literature in China and abroad and research status of Chinese medicinal monomers， Chinese medicinal formulations， and combinations with physical therapy in increasing osteoblast secretion， promoting OPG expression， enhancing cytokine expression levels， and inhibiting osteoclast activity for the prevention and treatment of ONFH. This paper is expected to provide new ideas and directions for TCM in the prevention and treatment of ONFH.

Duchenne muscular dystrophy: RANK/RANKL/OPG (receptor activator of nuclear factor-kB/RANK ligand/osteoprotegerin) system and glucocorticoids / Distrofia muscular de Duchenne: el sistema RANK/RANKL/OPG (receptor activador del factor nuclear-kB/ligando de RANK/osteoprotegerina) y glucocorticoides

Abstract Duchenne muscular dystrophy (DMD) is an X-linked inherited disorder. Patients present with decreased bone mineral density (BMD) due to glucocorticoid therapy and progressive muscle weakness. Bone remodeling allows bone volume and structure to be maintained and controlled by local and systemic factors. These include the receptor activator of the nuclear factor-kB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system, a determining pathway in the balance between bone formation and resorption. Disruptions in this complex, caused by factors such as glucocorticoids, can affect bone metabolism. The extensive action of the RANK/RANKL/OPG pathway suggests an influence on dystrophic muscle pathophysiology. This review aimed to highlight some aspects of the RANK/RANKL/OPG system, the effect of glucocorticoids on this pathway, and the pathophysiology of the patient with DMD.

Resumen La distrofia muscular de Duchenne (DMD) es un trastorno hereditario ligado al cromosoma X. Los pacientes presentan una disminución de la densidad mineral ósea (DMO) debido a los efectos adversos del tratamiento con glucocorticoides y a la debilidad muscular progresiva. El remodelado óseo permite mantener el volumen y la estructura ósea, proceso controlado por factores locales y sistémicos. Entre ellos destaca el sistema del receptor activador del factor nuclear-kB (RANK), su ligando natural RANKL (RANKL) y la osteoprotegerina (OPG), una vía determinante en el equilibrio entre la resorción y formación ósea. Las alteraciones en este complejo, originadas por factores como los glucocorticoides, pueden afectar el metabolismo óseo. La amplia acción de RANKL y OPG ha sugerido una influencia en la fisiopatología de la DMD. El objetivo de esta revisión fue destacar algunos aspectos del sistema RANK/RANKL/OPG, el efecto de los glucocorticoides en esta vía y la fisiopatología del paciente con DMD.

Systemic lithium chloride administration improves tooth extraction wound healing in estrogen-deficient rats

Abstract The purpose of this investigation was to evaluate the effects of lithium chloride (LiCl) on the socket healing of estrogen-deficient rats. Seventy-two rats were allocated into one of the following groups: Control, Ovariectomy and LiCl (150 mg/kg/2 every other day orally) + Ovariectomy. Animals received LiCl or water from the 14th day post-ovariectomy, until the completion of the experiment. On the 21st day after ovariectomy, the first molars were extracted. Rats were euthanized on the 10th, 20th and 30th days following extractions. Bone healing (BH), TRAP positive cells and immunohistochemical staining for OPG, RANKL, BSP, OPN and OCN were evaluated. The Ovariectomy group presented decreased BH compared to the LiCl group at 10 days, and the lowest BH at 20 days (p<0.05). At 30 days, the Ovariectomy and LiCl-groups presented lower BH than that of the Control (p<0.05). The number of TRAP-stained cells was the lowest in the LiCl group at 20 days and the highest in the Ovariectomy group at 30 days (p<0.05). At 10 days of healing, the LiCl group demonstrated stronger staining for all bone markers when compared to the other groups, while the Ovariectomy group presented higher RANKL expression than that of the Control (p<0.05). LiCl enhanced bone healing in rats with estrogen deficiency, particularly in the initial healing phases. However, as data on the effects of lithium chloride on bone tissue are still preliminary, more studies related to its toxicity and protocol of administration are necessary before its application in clinical practice.

Resumo O objetivo deste estudo foi avaliar os efeitos do Cloreto de Lítio (ClLi) na cicatrização de alvéolos de ratas deficientes em estrogênio. Setenta e duas ratas foram alocadas em um dos seguintes grupos: Controle, Ovariectomia e Cloreto de Lítio (150mg/kg/ oralmente a cada 2 dias) + ovarectomia. Os animais receberam ClLi ou água a partir do 14º dia pós-ovariectomia, até a conclusão do experimento. No 21º dia após a ovariectomia, os primeiros molares foram extraídos. As ratas foram sacrificadas nos dias 10, 20 e 30 após extrações. Foram avaliadas a cicatrização óssea (BH), células positivas para TRAP e coloração imuno-histoquímica para OPG, RANKL, BSP, OPN e OCN. O grupo Ovariectomia apresentou BH diminuída em comparação ao grupo LiCl aos 10 dias e a menor BH aos 20 dias (p<0,05). Aos 30 dias, os grupos Ovariectomia e LiCl apresentaram menor BH do que o Controle (p<0,05). O número de células positivas para TRAP foi menor no grupo ClLi em 20 dias e o maior no grupo Ovariectomia em 30 dias (p<0,05). Aos 10 dias de cicatrização, o grupo ClLi demonstrou imunomarcação mais intensa em todos os marcadores testados quando comparado aos outros grupos, enquanto o grupo Ovariectomia apresentou maior expressão de RANKL do que a do controle (p<0,05). O ClLi melhorou a cicatrização óssea em ratos com deficiência de estrogênio, particularmente nas fases iniciais do reparo. No entanto, como os dados sobre os efeitos do cloreto de lítio no tecido ósseo ainda são preliminares, mais estudos relacionados à sua toxicidade e protocolo de administração são necessários antes de sua aplicação na prática clínica.

Lymphocyte B and Th17 chemotactic cytokine levels in peri-implant crevicular fluid of patients with healthy, peri-mucositis, and peri-implantitis implants / 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.

La periimplantitis es una de las principales causas de falla y pérdida del implante, y su diagnóstico temprano no es factible debido a la baja sensibilidad de los métodos actuales. En este estudio transversal exploratorio, se estudió el potencial diagnóstico de los niveles de citocinas quimiotácticas de linfocitos B y Th17 en el líquido crevicular periimplantario (LCPI) en 54 pacientes con implantes sanos, peri-mucositis o periimplantitis. Se recogió líquido crevicular periimplantario y se cuantificaron los niveles de las moléculas estudiadas mediante Luminex assay. Las concentraciones de CCL-20 MIP-3 alfa, BAFF/BLYS, RANKL y la concentración de OPG en LCPI se analizaron en el contexto de las variables clínicas y del paciente (tabaquismo, antecedentes de periodontitis, diagnóstico periodontal, supervivencia del implante, supuración, sangrado al sondaje, profundidad de sondeo periodontal, nivel de inserción clínica, media de la profundidad de sondeo del implante e índice de placa). Los pacientes con periimplantitis parecen tener una sobrerregulación del eje RANKL/BAFF-BLyS. Este fenómeno debe investigarse en profundidad en futuros estudios con un tamaño de muestra mayor.

Evaluation of the effect of topical and systemic ozone application in periodontitis: an experimental study in rats

Abstract Objective: The goal of the present study was to determine the effect of systemic and topical ozone application on alveolar bone loss (ABL) by evaluating the effect of Hypoxia-inducible factor −1 alpha (HIF-1-α) and receptor activator of NF-kB ligand (RANKL)-positive cells on histopathological and immunohistochemical changes in a rat periodontitis model. Methodology: Thirty male Wistar rats were divided into three groups: 1) Group C (control group); 2) Group SO (systemic ozone group) and 3) Group TO (topical ozone group). Experimental periodontitis was induced with a 3/0 silk suture placed at the mandibular left first molars of rats, and the suture was removed 14 days later. Ozone gas was injected intraperitoneally (0.7 mg/kg) in SO group. Topical ozone application protocol was performed using an ozone generator at 80% concentration (4th grade) 90- degree probe for the duration of 30 s. Both ozone applications were carried out for two weeks at intervals of two days. Histomorphometric and immunohistochemical analysis were performed. Results: ABL was significantly lower in Group SO compared to Group C (p: 0.0052). HIF-1α- positive cells were significantly lower in Group TO than in Group C (p: 0.0043). RANKL-positive cells were significantly lower in Group SO and in Group TO compared to the control group (p: 0.0033, p: 0.0075, respectively). Conclusion: Both ozone applications decreased RANKL-positive cell counts, TO application decreased HIF-1-α positive cells counts, and SO application was found to be more effective in reducing ABL compared to control group.

Receptor Activator of Nuclear Factor-Kappa Ligand and Osteoprotegerin Expressions on Hyperglycemic Wistar Rats (Rattus Novergicus) During Orthodontic Tooth Movement

Abstract Objective: To investigate the differences of receptor activator of nuclear factor-κB ligand (RANKL) and Osteoprotegerin (OPG) expressions between normoglycemic and hyperglycemic Wistar rats (Rattus Novergicus) during Orthodontic Tooth Movement (OTM). Material and Methods: This study was true experimental with post-test group only. Thirty-two healthy male Wistar rats, weighted around 200-250 grams, 12-20 weeks old, were used as OTM animal study. They were divided into 2 groups (n=16), normoglycemic rats (normal blood glucose 80-120 mg/dl) and hyperglycemic rats (>250 mg/dl) induced by Streptozotocin with a dose of 30 mg in PBS injection intraperitoneally. A NiTi closed coil spring was mounted between maxillary first molar and incisors with the light force 10gf/mm2 in both groups to induce OTM. The studied animals were then terminated on days 1, 3, 6, and 9, respectively, and premaxilla was extracted. RANKL and OPG expression were examined utilizing immunohistochemistry (IHC) analysis. One-way ANOVA and Tukey HSD (p<0.05) were utilized to analyze the differences in the expression of RANKL and OPG between groups. Results: The hyperglycemic group on day 1, 9 rats showed a significant increase in the expression of RANKL, whereas OPG expression decreased significantly on days 1, 3, and 9. Conclusion: There was a significant increase of RANKL expression and a decrease of OPG expression in hyperglycemic rats as documented immunohistochemically.

N-acetyl-l-cysteine controls osteoclastogenesis through regulating Th17 differentiation and RANKL in rheumatoid arthritis

BACKGROUND/AIMS: This study aimed to determine the regulatory role of N-acetyl-l-cysteine (NAC), an antioxidant, in interleukin 17 (IL-17)-induced osteoclast differentiation in rheumatoid arthritis (RA). METHODS: After RA synovial fibroblasts were stimulated by IL-17, the expression and production of receptor activator of nuclear factor κ-B ligand (RANKL) was determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Osteoclastogenesis was also determined after co-cultures of IL-17-stimulated RA synovial fibroblasts, Th17 cells and various concentrations of NAC with monocytes. After human peripheral CD4⁺ T cells were cultured with NAC under Th17 condition, IL-17, interferon γ, IL-4, Foxp3, RANKL, and IL-2 expression and production was determined by flow cytometry or ELISA. RESULTS: When RA synovial fibroblasts were stimulated by IL-17, IL-17 stimulated the production of RANKL, and NAC reduced the IL-17-induced RANKL production in a dose-dependent manner. NAC decreased IL-17-activated phosphorylation of mammalian target of rapamycin, c-Jun N-terminal kinase, and inhibitor of κB. When human peripheral blood CD14⁺ monocytes were cultured with macrophage colony-stimulating factor and IL-17 or RANKL, osteoclasts were differentiated, and NAC reduced the osteoclastogenesis. After human peripheral CD4⁺ T cells were co-cultured with IL-17-pretreated RA synovial fibroblasts or Th17 cells, NAC reduced their osteoclastogenesis. Under Th17 polarizing condition, NAC decreased Th17 cell differentiation and IL-17 and RANKL production. CONCLUSIONS: NAC inhibits the IL-17-induced RANKL production in RA synovial fibroblasts and IL-17-induced osteoclast differentiation. NAC also reduced Th17 polarization. NAC could be a supplementary therapeutic option for inflammatory and bony destructive processes in RA.

Effect of salmon calcitonin on RANK/RANKL/OPG osteolysis pathway in human macrophages after particle induction / 中国医师杂志

Objective To explore the effect of salmon calcitonin on the receptor activator of NF-κB/receptor activator of NF-κB ligand/osteoprotegerin (RANK/RANKL/OPG) osteolysis pathway in human macrophages after particles induction.Methods The polyethylene wear particles were extracted from the periacetabular boundary membrane tissue of a patient with hip prosthesis loosening.The optimal reaction cell concentration of human macrophages to polyethylene wear particles (with a concentration of 0.1 mg/ml) was measured by methyl thiazolyl tetrazolium (MTT) assay.Particles were used to stimulate human macrophages,while salmon calcitonin with different drug concentrations was used for intervention.They were randomly divided into five groups,with six parts in each group:Group A,control group;Group B,particle group;Group C,particle + salmon calcitonin (10-8 mol/L) group;Group D,particle + salmon calcitonin (10-10 mol/L) group;Group E,particle+salmon calcitonin (10-12 mol/L) group.After cocultured for 48 hours,quantitative polymerase chain reaction (qPCR) assay was used to detect the mRNA expression of RANK,RANKL and OPG in macrophages.Results After induction with particles,Group B had a higher expression in RANK and RANKL,and lower OPG expression than Group A.After salmon calcitonin intervention,the expression of RANK and RANKL were significantly decreased,and OPG expression was significantly increased.Group B had the highest RANKL/OPG rate.After drug intervention,the RANKL/OPG rate in C,D,E group were reduced.Conclusions The particles can induce the transformation of macrophages into osteoclasts.In addition to directly inhibiting osteoclast activity,salmon calcitonin prevents macrophage from differentiating into osteoclasts through modulating RANKL/RANK/OPG signaling pathway.

The function of OPG/RANKL/RANK system in tumor bone metastasis / 中华检验医学杂志

Tumor bone metastasis is one of the main causes of treatment failure in tumor.Since tumor bone metastasis is a complex process,the exact etiopathogenesis of tumor bone metastasis has not been clarified.Recent studies demonstrated that osteoprotegerin/receptor activator of NF-κB ligand/receptor activator of NF-κB (OPG/RANKL/RANK) system plays an important role during the development and progression of tumor bone metastasis.In this review,the research progress of OPG/RANKL/RANK system,including biological functions,the bone microenvironment regulation,the detection method,the diagnosis and treatment of tumor will be summerized.

Intravenous Immunoglobulin Controls Th17 Cell-Mediated Osteoclastogenesis

The purpose of this study was to determine the regulatory role of intravenous Ig (IVIg) in Th17 cytokine–induced RANK ligand (RANKL) expression and osteoclast (OC) differentiation from OC precursors (pre-OC). Human CD14⁺ monocytes were isolated and stimulated by Th17 cytokines (IL-17, IL-21, and IL-22) and RANKL expression was investigated using a real-time PCR. CD14⁺ monocytes were incubated with RANKL, Th17 cytokines, and M-CSF, with/without IVIg, and OC differentiation was determined by counting tartrate-resistant acid phosphatase-positive multinucleated cells. OC differentiation was investigated after monocytes were cocultured with Th17 cells in the presence of IVIg. Th17 cell differentiation was determined using enzyme-linked immunosorbent assay and flow cytometry after CD4⁺ T cells were cultured with IVIg under Th17 condition. Th17 cytokines stimulated monocytes to express RANKL and IVIg suppressed the Th17 cytokine-induced RANKL expression. OCs were differentiated when pre-OC were cocultured with RANKL or Th17 cytokines and IVIg reduced the osteoclastogenesis. IVIg also decreased osteoclastogenesis when pre-OC were cocultured with Th17 cells. IVIg decreased both Th17 and Th1 cell differentiation while it did not affect Treg cell differentiation. In summary, IVIg inhibited Th17 cytokine-induced RANKL expression and OC differentiation. IVIg reduced osteoclastogenesis when monocytes were cocultured with Th17 cells. IVIg also reduced Th17 polarization. IVIg could be a new therapeutic option for Th17 cell–mediated osteoclastogenesis.

Quantification of pro-inflammatory cytokines and osteoclastogenesis markers in successful and failed orthodontic mini-implants

Abstract Objectives: Miniscrew has been frequently used, considering that anchorage control is a critical point in orthodontic treatment, and its failure, the main adverse problem. Using two groups of stable (successful) and unstable (failed) mini-implants, this in vivo study aimed to quantify proinflammatory cytokines IL-1 α, IL-6, IL-17, and TNF-α and osteoclastogenesis marker RANK, RANKL, and OPG in gingival tissue, using the real-time polymerase chain reaction technique. Methodology: Thirteen patients of both sexes (11-49 years old) under orthodontic treatment were selected, obtaining 11 successful and 7 failed mini-implants. The mini-implants were placed and removed by the same surgeon, in both jaws. The mean time of permanence in the mouth was 29.4 months for successful and 7.6 months for failed mini-implants. At removal time, peri-mini-implant gingival tissue samples were collected and processed for quantification of the proinflammatory cytokines and osteoclastogenesis markers. Nonparametric Wilcoxon rank-sum test considering the clusters and Kruskal-Wallis test were used for statistical analysis (α=0.05). Results: No significant difference (p>0.05) was observed between the groups for either quantification of cytokines or osteoclastogenesis markers, except for IL-6 (p<0.05). Conclusions: It may be concluded that the expression of IL-1α, IL-17, TNF-α, RANK, RANKL, and OPG in peri-implant gingival tissue were not determinant for mini-implant stability loss, but the higher IL-6 expression could be associated with mini-implant failure.

Chronic Periodontitis and RANKL/OPG Ratio in Peri-Implant Mucosae Inflammation

Abstract tHistory of chronic periodontitis (CP) is a risk factor for oseointegration failure. The osteoclastogenesis system (RANK, RANKL and OPG) is critical for bone homeostatic control. We investigated the levels of OPG and RANKL in peri-implant tissues from volunteers with and without a history of CP and their association with mucosae inflammation. This is a single-blind case-contro study. Diagnosis of a history of CP and peri-implant examination was performed on 46 volunteers, divided into control (without history of CP, n=26) and CP group (with history of CP, n=20). Gingival biopsies were harvested during implant exposure. Quantitative PCR evaluated OPG/RANKL mRNA expressions. OPG and RANKL proteins were analyzed by western blot and immunohistochemistry assay. The chi-square test analyzed the significance of nominal variables between groups while continuous variables were analyzed by T-test or Mann-Whitney test, after Shapiro-Wilk test evaluation. The 2-ΔΔCT Livak method calculation evaluated the gene expression. Values of p<0.05 were considered statistically significant. Volunteers with CP history had 23 times higher chance of developing mucosae inflammation. High mucosae levels of RANKL (p=0.04) and RANKL/OPG (p=0.001) mRNA expressions were observed in CP group. CP volunteers showed increased RANKL protein levels in opposition to decreased OPG expression. Even without active periodontitis, volunteers with a history of CP had elevated gingival levels of RANKL/OPG and higher correlation with peri-implant mucosae inflammation and implant loss.

Resumo A história de periodontite crônica (CP) é um fator de risco para falhas na osseointegração. O sistema de osteoclastogênese (RANK, RANKL e OPG) é crucial para o controle da homeostase óssea. O objetivo deste estudo foi investigar os níveis de OPG e RANKL no tecido peri-implantar de voluntários com e sem histórico de CP e sua associação com inflamação da mucosa. Este é um estudo tipo caso-controle. O exame para diagnóstico de CP e na região peri-implantar foi realizado em 46 voluntários, divididos em controle (sem história CP, n=26) e grupo CP (com histórico de CP, n=20). Descartes gengivais foram obtidos durante a exposição do implante. PCR quantitativo avaliou a expressão do RNAm de OPG/RANKL. As proteínas OPG e RANKL foram analisadas por western blot e imunohistoquímica. O teste do qui-quadrado analisou a significância entre as variáveis nominais enquanto as variáveis contínuas foram analisadas pelo teste-t e Mann-Whitney, após o teste de Shapiro-wilk. O método do Livak 2--ΔΔCT avaliou a expressão gênica. Os voluntários com CP apresentaram 23 vezes mais chances de desenvolver inflamação da mucosa. Expressão elevada no RNAm de RANKL (p=0.04) e RANKL/OPG (p=0.001) foram observadas no grupo CP. Voluntários com CP mostraram aumento dos níveis da proteína RANKL em contraste com diminuída expressão de OPG. Mesmo sem periodontite ativa, voluntários com histórico de CP apresentaram elevado nível gengival de RANKL/OPG e alta correlação com inflamação peri-implantar e perda do implante.

Clinical, radiologic and pathologic features of giant cell tumor of bone treated with denosumab / 中华病理学杂志

Objective@#To investigate the radiological and histopathological features of giant cell tumor of bone treated with RANKL inhibitor denosumab.@*Methods@#Eleven cases were retrieved from the surgical pathology records between March 2015 and June 2017 in Beijing Jishuitan Hospital. Formalin fixed, paraffin embedded specimens were collected and the histological features were evaluated. The imaging features including X ray, magnetic resonance imaging, and computed tomography were also reviewed.@*Results@#These 11 cases of giant cell tumor of bone were derived from five female and six male patients, with age ranged from 20 to 62 years (mean age, 35 years). The tumors were located in the sacrum (6 cases), femur (2 cases), radius (1 case), tibia (1 case) and patella (1 case), respectively. Histologically, all cases showed depletion of giant cells, proliferation of mononuclear cells and different degrees of ossification 3 to 6 months after denosumab therapy. Radiography showed marked osteosclerosis and sclerotic rim formation. Three cases of the sacrum recurred after 5, 6 and 11 months of surgery, and the remaining cases showed no recurrence within follow-up of 1 to 14 months.@*Conclusions@#Denosumab treated giant cell tumors morphologically differ from untreated tumors. Careful attention to a history of denosumab administration is crucial to avoid misdiagnosis and to allow proper differentiation from other tumors and tumor-like lesions.

The effects of chitosan oligosaccharides on OPG and RANKL expression in a rat osteoarthritis model

Abstract Purpose: To investigate the effect of chitosan oligosaccharides (COS) against osteoarthritis (OA) and preliminarily discuss the osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL) and RANK expression in a rat OA model. Methods: Thirty-six 6-week-old Male SD rats were randomly divided into three groups: sham-operated group(CON), OA-induction group(OA), COS intervention group(n=12/group). At 4 weeks after the operation, COS (50 ul) intervention weekily for consecutive 5 weeks. The OA and CON groups received an injection of 50 ul physiological saline. At death, 11 weeks following surgery, cartilage was harvested and total RNA and protein were extracted. Both the morphological changes of the cartilage were observed and harvested the total RNA and protein. Meanwhile, the expression of OPG, RANKL and RANK in cartilage were determined. Results: The expression of OPG and RANKL were both enhanced in the cartilage of the OA model. Compared with the OA group, COS treatment improved the cartilage damage (both extent and grade). Furthermore, the COS group showed highly OPG and lower RANKL. Simultaneously, COS treatment upregulated the ratio of OPG/RANKL and downregulated the RANKL/RANK. Conclusion: Chitosan oligosaccharides may be used as a unique biological agent to prevent and treat osteoarthritis, and this effect is associated with modulation of the expression of osteoprotegerin and receptor activator of NF-κB ligand.

Denosumab for the treatment of osteoporosis

Denosumab, a specific inhibitor of RANK ligand, is a novel therapy for postmenopausal osteoporosis and related disorders. An extensive clinical development program has evaluated the clinical efficacy and safety of denosumab with several thousand patients being followed for up to 10 years. Combined with more than six years of postmarketing experience, these studies provide substantial confidence that denosumab is a convenient and appropriate treatment for patients, including Asians, at high risk for fracture. This review will summarize the clinical development of denosumab and lessons learned since its approval for clinical use in 2010.

Effect of denosumab combined with surgery on sacral giant cell tumor / 肿瘤研究与临床

Objective To evaluate the clinical benefits of denosumab in treatment of sacral giant cell tumor of bone(GCTB) when used preoperatively or postoperatively along with surgery, and to analysis the improvement of sacral nerve function. Methods Thirty patients diagnosed as sacral GCTB in Musculoskeletal Tumor Center of Peking University People's Hospital from April 2014 to July 2016 were divided into control group (10 cases), post-operative group (9 cases), and neoadjuvant group (11 cases). Patients in the post-operative and neoadjuvant group were treated with 120 mg of subcutaneous denosumab every 4 weeks with loading doses on days 8 and 15 of the first cycle. Results Three patients in the control cohort 1 had recurrence (3/10), no recurrence occurred in the post-operative group (0/9), and 3 patients in the neoadjuvant group had recurrence(3/11).There were no significant differences in event-free survival(EFS) among the three groups (P = 0.133). The objective response rate (OTR) was 63.6 % (7/11) in the neoadjuvant group based on the RECIST 1.1 criteria for evaluating the efficacy of solid tumors. Five cases had significant pain improvement (defined 2 points improved) and had much better bladder and bowel functions. Four patients were able to have their indwelling catheters removed after neoadjuvant denosumab treatment. Conclusions Neoadjuvant therapy with denosumab can relieve the symptoms and neurologic deficits caused by nerve compression and can diminish the intraoperative blood loss. Surgical removal of the tumor is still the basic treatment of sacral GCTB.

Effects of different concentration of IL-17 on the expression of RANKL and OPG in human periodontal ligament fibroblasts / 重庆医学

Objective To study the effects of different concentration of interleukin(IL)-17 on the expression of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprogeterin (OPG) in human periodontal ligament fibroblasts (HPDLF) and explore the relationship between IL-17 and orthodontic root resorption.Methods HPDLF cell line was established through the tissue pieces culture method in vitro.HPDLF were stimulated by IL-17 with five different concentrations(0,5,10,20,40 ng/mL) for 24 h.The expression level of mRNA and protein of RANKL and OPG in HPDLF were detected by RT-PCR and ELISA,respectively.Results HPDLF expressed RANKL and OPG in 0 ng/mL group.The expression amount of mRNA and protein of RANKL in HPDLF was positive correlation with the concentration of IL-17 in 0 to 20 ng/mL group.The expression amount of mRNA and protein of OPG was negative correlation with the concentration of IL-17 in 5 to 20 ng/mL group.The ralative RANKL/OPG ratio of mRNA and protein were positive correlation with the concentration of IL-17 in 0 to 20 ng/mL group.Conclusion HPDLF expresses RANKL and OPG in the absence of IL-17.IL-17 enhances the expression of RANKL and inhibits the expression of OPG in HPDLF.

Fexaramine Inhibits Receptor Activator of Nuclear Factor-κB Ligand-induced Osteoclast Formation via Nuclear Factor of Activated T Cells Signaling Pathways

BACKGROUND: Osteoclasts are bone resorbing cells and are responsible for bone erosion in diseases as diverse as osteoporosis, periodontitis, and rheumatoid arthritis. Fexaramine has been developed as an agonist for the farnesoid X receptor (FXR). This study investigated the effects of fexaramine on receptor activator of nuclear factor (NF)-κB ligand (RANKL)-induced osteoclast formation and signaling pathways. METHODS: Osteoclasts were formed by culturing mouse bone marrow-derived macrophages (BMMs) with macrophage colony-stimulating factor (M-CSF) and RANKL. Bone resorption assays were performed using dentine slices. The mRNA expression level was analyzed by real-time polymerase chain reaction. Western blotting assays were conducted to detect the expression or activation level of proteins. Lipopolysaccharide-induced osteoclast formation was performed using a mouse calvarial model. RESULTS: Fexaramine inhibited RANKL-induced osteoclast formation, without cytotoxicity. Furthermore, fexaramine diminished the RANKL-stimulated bone resorption. Mechanistically, fexaramine blocked the RANKL-triggered p38, extracellular signal-regulated kinase, and glycogen synthase kinase 3β phosphorylation, resulting in suppressed expression of c-Fos and NF of activated T cells (NFATc1). Consistent with the in vitro anti-osteoclastogenic effect, fexaramine suppressed lipopolysaccharide-induced osteoclast formation in the calvarial model. CONCLUSIONS: The present data suggest that fexaramine has an inhibitory effect on osteoclast differentiation and function, via downregulation of NFATc1 signaling pathways. Thus, fexaramine could be useful for the treatment of bone diseases associated with excessive bone resorption.

Can denosumab be a substitute, competitor, or complement to bisphosphonates?

Osteoblasts, originating from mesenchymal cells, make the receptor activator of the nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in order to control differentiation of activated osteoclasts, originating from hematopoietic stem cells. When the RANKL binds to the RANK of the pre-osteoclasts or mature osteoclasts, bone resorption increases. On the contrary, when OPG binds to the RANK, bone resorption decreases. Denosumab (AMG 162), like OPG (a decoy receptor), binds to the RANKL, and reduces binding between the RANK and the RANKL resulting in inhibition of osteoclastogenesis and reduction of bone resorption. Bisphosphonates (BPs), which bind to the bone mineral and occupy the site of resorption performed by activated osteoclasts, are still the drugs of choice to prevent and treat osteoporosis. The merits of denosumab are reversibility targeting the RANKL, lack of adverse gastrointestinal events, improved adherence due to convenient biannual subcutaneous administration, and potential use with impaired renal function. The known adverse reactions are musculoskeletal pain, increased infections with adverse dermatologic reactions, osteonecrosis of the jaw, hypersensitivity reaction, and hypocalcemia. Treatment with 60 mg of denosumab reduces the bone resorption marker, serum type 1 C-telopeptide, by 3 days, with maximum reduction occurring by 1 month. The mean time to maximum denosumab concentration is 10 days with a mean half-life of 25.4 days. In conclusion, the convenient biannual subcutaneous administration of 60 mg of denosumab can be considered as a first-line treatment for osteoporosis in cases of low compliance with BPs due to gastrointestinal trouble and impaired renal function.