Suppression of puerarin on polymethylmethacrylate-induced lesion of peri-implant by inhibiting NF-κB activation in vitro and in vivo

Puerarin (PR), a natural isoflavone isolated from Chinese traditional plant pueraria lobata, has attracted considerable attention due to its important biological and pharmacological activities. However, its effects on lesion of peri-implant and related mechanism of action are still not clear, which require further investigation. In this study, we evaluated the effects of PR on polymethylmethacrylate (PMMA)-induced lesion of peri-implant in vitro and in vivo, and explored its possible mechanism of action. Our results indicated that PR could inhibit PMMA-induced osteoclastogenesis in RAW264.7 cells with a dose-dependent manner in vitro and effectively down-regulate mRNA and protein expressions of matrix metalloprotein 9 (MMP-9), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and receptor activator of nuclear factor (NF)-κB (RANK), primarily via the suppression of NF-κB signaling. Furthermore, we found that PMMA induction could directly cause the phosphorylation of IκB and significantly promote the nuclear translocation of p65 in RAW264.7 cells. In other words, PR was able to dose-dependently attenuate the PMMA-induced nuclear translocation of p65 in RAW264.7 cells. In vivo, PR was observed to attenuate PMMA-induced osteoclastogenesis, osteolysis, mRNA expressions of receptor activator of nuclear factor (NF)-κB ligand (RANKL) and RANK, as well as protein levels of MMP-9, TNF-α, IL-6, and p65 in a murine calvarial osteolysis model. These findings suggested that PR might be a potential therapeutic drug to lesion of peri-implant, and provided new insights for understanding its possible mechanism.     

RANKL、RANK蛋白在胶质母细胞瘤组织中的表达及临床意义

目的:分析RANKL、RANK蛋白在胶质母细胞瘤组织中的表达及临床意义。方法:收集2017年10月至2019年10月于我科行手术治疗的21例胶质母细胞瘤患者的临床资料，用蛋白印迹试验检测肿瘤中心组织、瘤周组织、皮层造瘘脑组织中RANKL、RANK表达情况，并对其进行统计学分析。结果:肿瘤中心组织RANKL表达高于瘤周组织，有统计学差异(P=0.032)；瘤周组织高于皮层造瘘脑组织，有统计学差异(P=0.024)。瘤周组织RANK表达明显高于肿瘤中心组织，有统计学差异(P=0.006)；肿瘤中心组织高于皮层造瘘脑组织，有统计学差异(P=0.028)。结论:肿瘤中心组织中RANKL表达高于瘤周组织、脑组织，而瘤周组织中RANK明显高于肿瘤中心组织、肿瘤中心组织高于脑组织，我们认为RANKL/RANK通路可能在胶质母细胞瘤侵袭过程中起重要作用，有待后续进一步试验。     

薯蓣皂苷片对类风湿性关节炎大鼠血清OPG/RANKL水平表达的干预作用

目的观察薯蓣皂苷片对类风湿性关节炎模型大鼠血清骨保护素(OPG)、核因子-κB受体活化因子配体(RANKL)表达水平的影响。方法 SD大鼠,随机分为6组,每组10只,其中选取10只作为正常组,其余大鼠采用弗氏完全佐剂复制类风湿性关节炎动物模型,并将造模成功的类风湿性关节炎大鼠随机分为模型组、阳性组(甲氨蝶呤组,3.8mg·kg~(-1))、薯蓣皂苷片高、中、低剂量组(10 mg·mL~(-1)、20 mg·mL~(-1)、30mg·mL~(-1)),连续灌胃给药治疗24 d后处死,采用ELISA法检测血清OPG、RANKL水平。结果薯蓣皂苷片各剂量组大鼠血清OPG、RANKL水平分别为(95.27±4.24)、(76.44±4.09)、(69.26±5.63)pmol·L~(-1)和(96.07±4.94)、(85.41±3.75)、(67.53±2.23)pmol·L~(-1),与模型组((53.92±2.83)pmol·L~(-1)和(116.18±3.02)pmol·L~(-1))相比均有显著性差异(P0.05);OPG/RANKL比值显著高于模型组。结论薯蓣皂苷片可能通过调整OPG/RANKL动态平衡而对破骨细胞功能产生影响,从而防止骨破坏。     

Medication-related osteonecrosis of the jaw: An institution’s experience

ABSTRACT

Objectives

This study aimed to evaluate and report the outcomes associated with the management of patients who were treated surgically for medication-related osteonecrosis of the jaw (MRONJ).Methods: Demographic and medical profiles of patients with a diagnosis of MRONJ were created. The type of surgical treatment, complications, and treatment outcomes were identified.Results: Twenty-one patients with an average age of 68.42 years (range 40–90 years) were included. Nineteen patients had only mandible involvement, one patient had only maxilla involvement, and one patient had both mandible and maxilla involvement. Thirteen patients underwent marginal resections. Eight patients underwent segmental resection of the mandible with immediate reconstruction. Nineteen patients healed without any complications. Two patients who had undergone segmental resection of the mandible experienced postoperative complications and needed a second surgery to achieve primary closure.Discussion: Advanced MRONJ can effectively be treated with resective surgery in combination with medical treatment.     

Cytokine pattern determines the progression of experimental periodontal disease induced by Actinobacillus actinomycetemcomitans through the modulation of MMPs, RANKL, and their physiological inhibitors

OBJECTIVE: Inflammatory and immune reactions raised in response to periodontopathogens are thought to trigger periodontal tissue destruction. We therefore investigated the expression of matrix metalloproteinases (MMPs) and the osteoclastogenic factor RANKL (receptor activator of nuclear factor-kappaB ligand), their respective inhibitors TIMPs (tissue inhibitors of metalloproteinases) and OPG (osteoprotegerin) and their possible correlation with the expression of inflammatory and regulatory cytokines in the course of experimental periodontal disease in mice. METHODS: We characterized the time course of leukocyte migration and alveolar bone loss in C57BL/6 mice infected with Actinobacillus actinomycetemcomitans. Quantitative polymerase chain reaction (RealTime PCR) and ELISA were performed to determine the expression of MMPs, TIMPs, RANKL, OPG and cathepsin K, interleukin-1beta, tumor necrosis factor-alpha, interferon-gamma, interleukin-12, interleukin-4 and interleukin-10 in periodontal tissue samples harvested throughout the course of experimental disease. RESULTS: Oral inoculation of A. actinomycetemcomitans results in an intense and widespread migration of leukocytes to the gingival tissues, besides marked alveolar bone resorption. Our data also demonstrate two distinct patterns of MMP/TIMP and RANKL/OPG expression in the course of experimental periodontal disease. The expression of MMPs (MMP-1, 2 and 9) and RANKL was correlated with the expression of interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma, in a time period characterized by the intense increase of inflammatory reaction and alveolar bone loss. On the other hand, interleukin-4 and interleukin-10 were associated with higher expression of TIMPs (TIMP 1, 2 and 3) and OPG, with a lower expression of MMPs and RANKL, and with reduced rates of increase of cellular infiltration in periodontal tissues and alveolar bone loss. CONCLUSIONS: It is possible that the pattern of cytokines produced in periodontal tissues determines the progression and the severity of experimental periodontal disease, controlling the breakdown of soft and bone tissues through the balance between MMPs/TIMP and RANKL/OPG expression in gingival tissues.     

Soluble RANKL in crevicular fluid of dental implants: a pilot study

Background Receptor activator of NF‐κB ligand (RANKL), a member of the tumor necrosis factor superfamily, is a key mediator of osteoclast formation, activation, and survival. Thus, it is reasonable to hypothesize that there might be a functional relationship between RANKL expression and peri‐implantitis. Purpose This pilot study was performed to determine the reference levels for soluble RANKL (sRANKL) in peri‐implant crevicular fluid and to correlate them with the clinical parameters associated with inflammatory reactions and bone destruction. Materials and Methods The clinical parameters probing depth (PD), modified bleeding index (MBI), and modified plaque index (MPI) served as indicators for bone resorption and inflammation. Exclusion criteria for calculations were the detection limit of the immunoassay and the minimum acceptable crevicular volume for measurement. From the 84 collected samples of 16 patients, 30–84 years of age, with a total of 19 implants, 29 met these criteria. The absolute amount of sRANKL within crevicular fluid adsorbed to filter strips was a median of 0.18 femtomol (fmol; range, 0.08–0.53) and 0.26 nM (range, 0.09–1.21) when normalized by volume. PD was 4 mm in median and varied within a range between 2 and 12 mm. Results Absolute amounts of sRANKL showed no correlation with the adsorbed volume and the clinical parameters PD, MBI, and MPI. When sRANKL was normalized by volume, no correlation with the clinical parameters PD, MBI, and MPI was observed either. The patients’ age was not associated with total sRANKL and the concentration of RANKL within crevicular fluid. Absolute levels of sRANKL and sRANKL concentration did not show any differences based on the sampling sites buccal and lingual, or on the patients’ gender. A significant difference in sRANKL concentration was detectable when samples from maxillary implants (0.31 nM median; range, 0.12–1.21) were compared with samples from mandibular implants (0.21 nM median; range, 0.09–0.6) (p=.03). Absolute levels of sRANKL were not different between the maxilla and the mandible. Conclusion Given the limited sample size, our data provide a basis for future prospective longitudinal studies on the possible relevance of sRANKL as a prognostic marker in peri‐implantitis, and for an understanding of the pathophysiologic process of the disease as a prerequisite for the design of treatment strategies.     

CSF-1, RANKL and OPG regulate osteoclastogenesis during murine tooth eruption

During tooth eruption, osteoclast-mediated bone resorption predominates in alveolar bone along the occlusal surface rather than in bone basal to the tooth. CSF-1, RANKL and OPG, regulatory molecules essential for osteoclastogenesis, are expressed during eruption. However, it is unclear if these cytokines exhibit an expression pattern that correlates with sites of osteoclastogenesis in vivo. To address this issue, mouse mandibles, isolated from 1 to 14 days postnatal, were analysed for osteoclast activity using tartrate-resistant acid phosphatase (TRAP) staining as well as colony-stimulating factor-1 (CSF-1), receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) mRNA expression using in situ hybridisation. Results showed that CSF-1, RANKL and OPG are expressed in a distinct temporal and spatial manner. In the occlusal region, osteoclast activity was maximal at day 5 and correlated with a relative high expression of CSF-1 and RANKL compared to OPG. In basal bone at this time point, osteoclast activity decreased despite persistent CSF-1 expression and was associated with increased expression of OPG compared to RANKL. By day 8, osteoclastogenesis declined and correlated with upregulation of OPG at the occlusal and basal regions, with this effect continuing throughout eruption. These findings suggest that the spatiotemporal pattern and relative abundance of CSF-1, RANKL and OPG during eruption are key determinants of site-specific osteoclast activity in bone surrounding the tooth. Targeting these cytokines to specific regions in alveolar bone may provide a mechanism for regulating osteoclastogenesis in dental disorders associated with altered tooth eruption.     

阳极氧化处理后的新型钛合金表面成骨细胞OPG、RANKL基因表达研究

目的:新型钛合金Ti-24Nb-4Zr-7.9Sn(TNZS)经过阳极氧化(anodic oxidation,AD)技术处理后,分析其表面的人成骨样MG63细胞骨保护素(osteoprotegerin,OPG)、细胞核因子-κB受体活化因子配体(RANKL)基因表达水平.方法:将人成骨样MG63细胞接种于Ti-6Al-4V、TNZS、AD-TNZS表面,采用半定量RT-PCR法检测OPG、RANKL mRNA的表达量.结果:人成骨样MG63细胞在AD-TNZS表面的OPGm RNA表达量有所提高,而RANKL mRNA的表达量3组材料间无明显差异.结论:阳极氧化处理的TNZS钛合金可能通过影响骨保护素、细胞核因子-κB受体活化因子配体调节成骨细胞、破骨细胞的平衡,从而促进种植体植入后的骨重建.     

Biological Changes on the Compressing Side of Orthodontic Teeth Stimulating by Soft laser

目的：研究在弱激光作用下接受正畸力作用的牙齿的压力侧出现的生物学变化，为临床应用弱激光加速牙齿移动提供理论依据。方法：实验动物分2组，每组20只。A组动物接受正畸力，B组动物除接受正畸力之外，还接受弱激光照射。采用免疫组化检测层连蛋白的组间表达变化，采用原位杂交检测RANKL(receptor activator of NF-kB ligand)mRNA的组间表达变化。结果：免疫组化结果表明，新生血管活跃的高峰期出现在接受正畸力的第7d。与A组相比，接受弱激光照射的B组呈现层连蛋白的高表达。同样，与A组相比，原位杂交检测发现在接受弱激光照射的B组中，正畸牙压力侧呈现RANKL mRNA的高表达。结论：弱激光照射后能够促进正畸牙压力侧血管新生(呈现层连蛋白高表达)，从而促进破骨细胞的分化激活。此外弱激光还能够促进破骨细胞活化因子RANKL的表达，增强正畸牙压力侧的破骨细胞的活性，加快骨改建。