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。     

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.     

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.     

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.     

Short communication: Serum osteoprotegerin concentrations in periparturient dairy cows

Dairy cows experience hypocalcemia at the onset of lactation; however, the contribution of bone metabolism to circulating Ca concentrations during the periparturient period is not well understood. Osteoprotegerin (OPG) protects against loss of skeletal mass by regulating osteoclastogenesis. We previously reported that the bone resorption increased around parturition in dairy cows from the perspective of bone markers in blood. The aim of this study was to explore osteoclastic bone resorption in periparturient dairy cows by measuring changes in serum OPG concentrations around calving. The OPG concentrations were evaluated in primiparous (n = 9) and multiparous (n = 9) cows at 21 d precalving and over 5 d after calving. Based on mixed model analyses, the multiparous cows had a higher serum OPG concentration than primiparous cows at precalving and exhibited a significant decline in serum OPG and Ca concentrations after calving. In contrast to multiparous cows, primiparous cows did not exhibit these changes. Therefore, we hypothesized that multiparous cows preserve their bone mineral content during late pregnancy and activate the osteoclastic bone resorption after calving. Based on our serum OPG data, we identified the different periparturient osteoclastic bone resorption patterns in healthy primiparous and multiparous dairy cows.     

高压和酶解辅助制备超微骨粉的工艺研究

为了提高畜禽骨的粉碎率,以促进畜禽骨的回收利用效率,本文以猪骨为原料,比较了高压处理和酶解次序对猪骨粉碎率的影响,并对猪骨高压处理后的酶解工艺采用响应面法优化和对所得骨粉的钙、磷营养物质含量进行了测定。结果发现,猪骨经高压处理后再酶解所得粉碎率较高压处理前酶解所得粉碎率高;响应面法优化猪骨高压处理后的酶解工艺,得出酶解温度为55℃、酶解时间为2.01 h、pH为7.00、加酶量为10363 U/g时所得猪骨的粉碎率最高(82.0%),比未优化前提高了9.45%;对粉碎前后猪骨中钙磷营养物质含量分析,得出高压和酶解辅助机械粉碎对猪骨中钙磷损失小。总之,高压处理后酶解辅助机械破碎法有效提高了猪骨的粉碎率,所得骨粉的钙磷营养物质与原始猪骨中的钙磷含量相似。