Ultrastructural and immunohistochemical study of the effect of sodium alendronate in the progression of experimental periodontitis in rats

The aim of the present research was to investigate the ultrastructural aspects and the immunoexpression of receptor activator of NFκB ligand (RANKL) and osteoprotegerin (OPG) on experimental periodontal disease of alendronate (ALN)‐treated rats. Male Wistar rats received daily injections of 2.5 mg/kg body weight of ALN during 7 days previously and 7, 14, and 21 days after the insertion of a 4.0 silk suture into the gingival sulcus around the right upper second molar. Specimens were fixed in 0.1% glutaraldehyde + 4% formaldehyde under microwave irradiation, decalcified in 4.13% EDTA and paraffin embedded for TRAP histochemistry and immunohistochemistry for RANKL and OPG, or embedded in Spurr epoxy resin for TEM analysis. ALN reduced the activity of osteoclasts and significantly decreased the resorption of the alveolar crest. In the control group the alveolar crest appeared resorbed by TRAP‐positive osteoclasts, which presented ultrastructural features of activated cells. The immunoexpression of RANKL was not inhibited by the drug; however, the expression of OPG was increased in the treated animals. The alveolar crest of ALN‐treated specimens at 21 days showed signs of osteonecrosis, like empty osteocyte lacunae, the exposed bone regions and bacterial infection. The results showed that ALN treatment in individuals with periodontal disease represents a risk of osteonecrosis because of the reduced activity of osteoclasts resultant of the increased immunoexpression of OPG. Microsc. Res. Tech. 77:902–909, 2014. © 2014 Wiley Periodicals, Inc.     

鲫鱼卵唾液酸糖蛋白对去卵巢大鼠骨质疏松症的改善作用

目的：从鲫鱼卵中提取唾液酸糖蛋白,研究其对去卵巢大鼠骨质疏松症的改善作用,并探究其作用机理。方法：采用切除大鼠双侧卵巢的方法建立骨质疏松症大鼠模型,灌胃鲫鱼卵唾液酸糖蛋白（400 mg/（kg·d））90 d后,分别检测大鼠尿液骨吸收指标（脱氧吡啶啉、钙、磷）、血清骨吸收指标（抗酒石酸酸性磷酸酶、组织蛋白酶K）、血清骨生成指标（骨源性碱性磷酸酶、骨钙素、Ⅰ型前胶原羧基端前肽）以及血清骨保护素（osteoprotegerin,OPG）、核因子κB受体活化因子（receptor activator for nuclear factor-κB,RANK）、核因子κB受体活化因子配体（receptor activator for nuclear factor-κB ligand,RANKL）含量。结果：鲫鱼卵唾液酸糖蛋白能显著降低骨质疏松症大鼠尿液脱氧吡啶啉（P＜0.01）、钙（P＜0.01）、磷（P＜0.01）含量和血清抗酒石酸酸性磷酸酶（P＜0.01）、组织蛋白酶K（P＜0.01）活性,防止大鼠骨吸收;显著降低血清骨源性碱性磷酸酶（P＜0.01）活性和骨钙素（P＜0.01）、Ⅰ型前胶原羧基端前肽（P＜0.01）含量,抑制大鼠高骨转换速率;显著上调OPG（P＜0.01）含量,下调RANKL（P＜0.01）含量,降低RANKL/OPG比值,抑制破骨细胞增殖分化,降低骨吸收。结论：鲫鱼卵唾液酸糖蛋白具有改善去卵巢大鼠骨质疏松症的作用,其作用机理可能与下调RANKL/OPG比值有关。     

白藜芦醇对去卵巢大鼠股骨骨保护素及核因子κB 受体活化子配体表达的影响

目的 观察白藜芦醇对去卵巢大鼠股骨骨保护素(OPG) 及核因子κB 受体活化子配体(RANKL) 表达的影响。 方法 健康3 月龄雌性SD大鼠48 只, 按体重随机分为6 组:假手术组(SHAM) 、单纯卵巢切除组(OVX) 、17β-雌二醇组(ERT, 0.1 mg·kg^-1 d^-1) 。低、中、高剂量白藜芦醇组(RL 、RM、RH, 每天分别给予10 、20 、40 mg kg白藜芦醇) 。除假手术组外其余各组均切除双侧卵巢。术后1周开始给药, 给药8 周后处死所有大鼠, 测定股骨骨密度(BMD) 及骨生物力学性能:弹性模量(ELASTIC) 、刚度(STIFFNESS) 、最大应力(M-STRESS) 及最大承载力(M-LORD) 。用免疫组织化学染色方法观察股骨OPG 、RANKL 的表达。 结果 与OVX 组比较, 20 、40 mg·kg^-1 d^-1白藜芦醇均能上调股骨OPG 表达(P <0.05) 。与OVX组比较, 20 、40 mg·kg-1·d-1 白藜芦醇均下调RANKL 的表达, 改善股骨骨密度及生物力学性能(P <0.05) 。 结论 白藜芦醇在体内可上调骨组织中OPG 的表达, 下调RANKL 的表达, 这可能是其改善股骨骨密度及生物力学性能的作用机制。     

二膦酸盐对人骨肉瘤细胞株MG-63细胞中OPG/RANKL表达的影响

目的研究二膦酸盐作用于人骨肉瘤细胞株MG-63细胞后,对细胞中成骨细胞护骨素(OPG)及细胞核因子κB受体活化因子配体(RANKL)表达的影响。方法人骨肉瘤细胞株MG-63细胞培养、传代后分为:二膦酸盐10μmol/L组、二膦酸盐50μmol/L组和阴性对照组3组,保温72 h后,应用RT-PCR和Western blot检测干预后OPG和RANKL mRNA和蛋白水平的表达。结果二膦酸盐作用于人骨肉瘤细胞株MG-63细胞后,细胞中OPG mRNA和蛋白水平表达升高,RANKL mRNA及蛋白水平则降低(均P<0.05)。结论二膦酸盐可能通过调节人骨肉瘤细胞株MG-63细胞OPG/RANKL轴的表达,抑制骨肉瘤的溶骨性破坏,对治疗人骨肉瘤有潜在价值。     

基于模糊神经骨素pH值的检测及控制

出于对提高明胶生产自动化程度、保证出胶质量的考虑,通过现场数据的采集,建立明胶骨素pH值的检测和浸泡液pH值的控制模型;结合C均值聚类和混合算法对FNN的检测和控制模型进行结构和参数辨识,在matlab环境下进行仿真,仿真结果表明,检测模型具有很好的学习能力和泛化能力,其误差可控制在[-0.1,0.1],控制模型使得浸泡液的pH值保持在4.0,与传统人工定时加酸相比,使得中和整个工序提前了5小时.     

Effects of Neuropeptides and Mechanical Loading on Bone Cell Resorption in Vitro

Neuropeptides such as vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) are present in nerve fibers of bone tissues and have been suggested to potentially regulate bone remodeling. Oscillatory fluid flow (OFF)-induced shear stress is a potent signal in mechanotransduction that is capable of regulating both anabolic and catabolic bone remodeling. However, the interaction between neuropeptides and mechanical induction in bone remodeling is poorly understood. In this study, we attempted to quantify the effects of combined neuropeptides and mechanical stimuli on mRNA and protein expression related to bone resorption. Neuropeptides (VIP or CGRP) and/or OFF-induced shear stress were applied to MC3T3-E1 pre-osteoblastic cells and changes in receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL) and osteoprotegerin (OPG) mRNA and protein levels were quantified. Neuropeptides and OFF-induced shear stress similarly decreased RANKL and increased OPG levels compared to control. Changes were not further enhanced with combined neuropeptides and OFF-induced shear stress. These results suggest that neuropeptides CGRP and VIP have an important role in suppressing bone resorptive activities through RANKL/OPG pathway, similar to mechanical loading.     

蒲公英提取物改善大鼠类风湿性关节炎的作用机制

本文研究了蒲公英提取物对类风湿性关节炎模型大鼠的作用机制。通过建立类风湿性关节炎模型,对大鼠进行病理学观察,并对治疗效果的相关指标如检测白介素-17(Interleukin-17,IL-17)、白介素-23(Interleukin-23,IL-23)、白介素-1(Interleukin-1,IL-1)、hs CRP、白介素-1β(Interleukin-1β,IL-1β)IL-1β、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、护骨素(Osteoprotegerin,OPG)、核因子KB配体受体激活因子(RANKL、RANK)水平进行检测。研究结果表明:高剂量蒲公英组大鼠足跖肿胀度(6.42±1.06)低于模型组大鼠足跖肿胀度(15.18±2.65)(p0.05),扭体(9.0±2.0)、缩足次数(8.5±1.5)高于模型组扭体(2.2±0.4)、缩足次数(2.4±0.5)。高剂量蒲公英组大鼠的IL-17、IL-23、IL-1、hs CRP、IL-1β、TNF-α等水平均低于模型组大鼠(p0.01)。高剂量蒲公英组大鼠的OPG(0.42±0.06)、RANKL(0.52±0.08)、RANK蛋白表达(0.45±0.05)显著低于模型组OPG(1.18±0.15)、RANKL(1.35±0.46)、RANK蛋白表达(1.23±0.45)(p0.01)。研究结果说明蒲公英提取物通过调控OPG/RANKL/RANK信号通路,抑制炎症因子水平表达,能显著改善风湿性关节炎模型大鼠的治疗效果。     

The Influence of Prenatal Fumonisin Exposure on Bone Properties,as well as OPG and RANKL Expression and Immunolocalization,in Newborn Offspring Is Sex and Dose Dependent

The current study examined the effects of exposure of pregnant dams to fumonisins (FBs; FB1 and FB2), from the seventh day of pregnancy to parturition, on offspring bone metabolism and properties. The rats were randomly divided into three groups intoxicated with FBs at either 0, 60, or 90 mg/kg b.w. Body weight and bone length were affected by fumonisin exposure, irrespective of sex or dose, while the negative and harmful effects of maternal FBs’ exposure on bone mechanical resistance were sex and dose dependent. The immunolocalization of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-Β ligand (RANKL), in bone and articular cartilage, indicated that the observed bone effects resulted from the FB-induced alterations in bone metabolism, which were confirmed by the changes observed in the Western blot expression of OPG and RANKL. It was concluded that the negative effects of prenatal FB exposure on the general growth and morphometry of the offspring bones, as a result of the altered expression of proteins responsible for bone metabolism, were dose and sex dependent.     

银耳多糖对人软骨细胞的增殖效应和抗炎作用

目的：骨关节炎（Osteoarthritis,OA）是一种常见的慢性关节性疾病,本研究旨在探究银耳多糖对骨关节炎细胞模型人软骨细胞T/C-28a2的增殖效应和抗炎作用。方法：通过MTT（3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide）和结晶紫染色实验检测银耳多糖对T/C-28a2细胞增殖活力和细胞毒性的影响;用脂多糖（Lipopolysaccharide,LPS）处理T/C-28a2细胞建立骨炎症模型,酶联免疫吸附测定（Enzyme-linked immunosorbent assay,ELISA）检测药物处理后细胞白介素-6（Interleukin-6,IL-6）的表达;利用蛋白免疫印迹（Western blot）检测药物处理后相关骨保护因子和炎症因子的表达;通过ROS活性氧释放实验检测药物对细胞的氧化应激水平和抗炎症反应。结果：银耳多糖能够促进人软骨细胞T/C-28a2的增殖活力,且没有明显的细胞毒性;使用LPS刺激软骨细胞模拟骨炎症的环境,药物处理后发现银耳多糖和硫酸软骨素处理能减少IL-6分泌从而抑制炎症发生;进一步Western blot检测发现银耳多糖刺激后,相关骨保护因子（Osteoprotegerin,OPG）的表达上调,而促凋亡相关蛋白Bax、细胞外信号调节激酶（Extracellular-signal-regulated kinases,ERK-MAPK）和核内转录因子κB（Nuclear factor-kappaB,NF-κB）的表达下调。活性氧（Reactive oxygen species,ROS）释放实验结果显示,银耳多糖和硫酸软骨素能够抑制细胞内ROS水平,抑制炎症反应的发生。结论：银耳多糖具有抑制骨关节炎的效用,可以在一定程度上保护软骨组织,抵抗细胞凋亡。本研究初步探讨了银耳多糖的抗炎作用及机制,为开发银耳多糖作为抗炎药物提供初步的实验依据。

     

Down-Regulation by Resveratrol of Basic Fibroblast Growth Factor-Stimulated Osteoprotegerin Synthesis through Suppression of Akt in Osteoblasts

It is firmly established that resveratrol, a natural food compound abundantly found in grape skins and red wine, has beneficial properties for human health. In the present study, we investigated the effect of basic fibroblast growth factor (FGF-2) on osteoprotegerin (OPG) synthesis in osteoblast-like MC3T3-E1 cells and whether resveratrol affects the OPG synthesis. FGF-2 stimulated both the OPG release and the expression of OPG mRNA. Resveratrol significantly suppressed the FGF-2-stimulated OPG release and the mRNA levels of OPG. SRT1720, an activator of SIRT1, reduced the FGF-2-induced OPG release and the OPG mRNA expression. PD98059, an inhibitor of upstream kinase activating p44/p42 mitogen-activated protein (MAP) kinase, had little effect on the FGF-2-stimulated OPG release. On the other hand, SB203580, an inhibitor of p38 MAP kinase, SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and Akt inhibitor suppressed the OPG release induced by FGF-2. Resveratrol failed to affect the FGF-2-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase or SAPK/JNK. The phosphorylation of Akt induced by FGF-2 was significantly suppressed by resveratrol or SRT1720. These findings strongly suggest that resveratrol down-regulates FGF-2-stimulated OPG synthesis through the suppression of the Akt pathway in osteoblasts and that the inhibitory effect of resveratrol is mediated at least in part by SIRT1 activation.