注射催产素对小鼠骨密度和成骨细胞分化影响的实验研究

目的通过建立雌性小鼠骨质疏松模型并给予催产素(oxytocin,OT)腹腔注射来验证催产素对骨代谢的调控作用。方法选取同批次2月龄雌性C57/B6小鼠15只,随机分成3组,每组5只:①对照组(C),②造模组(OVX),③造模+催产素注射组(OVX+OT)。注射催产素前和注射8周后分别测定各组小鼠左股骨和腰椎L4～6的骨密度,并提取小鼠骨髓细胞定向诱导分化,进行碱性磷酸酶(alkaline phosphatase,ALP)和Von Kossa染色以鉴定成骨细胞分化水平,通过q PCR检测分化相关因子表达水平。结果 OVX组小鼠骨密度较C组显著降低(P0. 001),OVX+OT组小鼠骨密度较OVX组显著升高(P0. 001)。ALP染色显示,OVX组成骨细胞分化较C组差,细胞集落最少; OVX+OT组成骨细胞分化情况较OVX组好,染色面积增加了322. 5%。Von Kossa染色发现OVX组细胞集落和钙结节较C组少且小,OVX+OT组细胞集落和钙结节较OVX组多,染色面积增加了62. 3%。而进一步添加催产素体外培养的成骨细胞其分化水平均比未加入催产素组有所提高。q PCR结果显示催产素能够促进成骨相关基因OPN、Runx2和Osterix的表达(P0. 001)。结论催产素促进小鼠体内的骨合成代谢作用,提示其对骨质疏松症治疗具有潜在用途。     

基于Cyclin D1基因敲减探讨健骨颗粒促进成骨细胞增殖的机理

目的验证Cyclin D1及其下游信号蛋白对成骨细胞增殖的调控作用,探讨健骨颗粒促进成骨细胞增殖的作用机制。方法培养成骨样细胞株UMR-106,运用CRISPR/Cas9技术敲减Cyclin D1基因后,将细胞分为基因敲减+生理盐水组(组1)、基因敲减+健骨颗粒组(组2)、病毒空载体细胞(组3,阴性对照)。未行基因敲减的细胞分为正常细胞+生理盐水组(组4)和正常细胞+健骨颗粒组(组5)。分别用生理盐水血清或健骨颗粒含药血清干预各组细胞24、48、72 h,通过CCK8法检测细胞增殖情况,利用Real time PCR检测Cyclin D1、Cyclin E、CDK 2、CDK 4、Rb及E2F-1基因的表达水平。结果经Western-bolt检测表明基因敲减的成骨细胞Cyclin D1蛋白表达明显下降。CCK8法检测结果显示,与组4相比,组5增殖速度变快(P0. 05),组3增殖速度无差异(P0. 05),组1和组2增殖速度均减慢(P0. 05);与组5相比,组2增殖速度减慢(P0. 01);与组1相比,组2增殖速度无统计学意义(P0. 05)。Real time PCR检测结果显示,与组4相比,组5 Cyclin D1、CDK2、CDK4、Cyclin E、Rb及E2F-1 mRNA的表达明显增高(P0. 05或P0. 01),组3表达无统计学意义(P0. 05),组1和组2表达明显降低(P0. 05或P0. 01);与组5相比,组2增殖速度减慢(P0. 01);与组1相比,组2无统计学意义(P0. 05)。结论 Cyclin D1及其下游信号蛋白是调控成骨细胞增殖的关键因素;健骨颗粒可以通过调节Cyclin D1及其下游信号蛋白促进成骨细胞增殖。     

骨免疫在口腔疾病中的作用研究进展

长期以来的研究表明先天免疫和后天免疫在宿主抵御外来微生物入侵的过程中起着至关重要的作用，而在这过程中也会同时造成宿主自身的组织或器官的损害。骨骼系统就是其中之一，在一些诸如类风湿性关节炎、牙周炎等疾病中，免疫系统的反应不仅起到去除外来致病菌的作用，还会同时造成骨骼系统的破坏。长期以来大部分的研究都致力于了解免疫系统对骨组织破坏的机制，而近些年来有研究开始探究骨反作用于免疫系统，由此衍生出了一个全新的研究领域——骨免疫。文章从骨免疫的机制、免疫与骨吸收作用通路以及在口腔相关疾病的作用机制等方面总结了近些年来相关的研究进展。     

梓醇防治骨质疏松症的研究进展

骨质疏松症常易导致骨折，致残和致死率高，严重影响患者生活质量。中药地黄及组方在临床上抗骨质疏松效果显著，已有越来越多的研究发现和报道了其活性成分梓醇在这方面的作用和机制，取得了一定的研究成果。本文将通过Pubmed、Web of science、中国知网和万方数据库等对于近10年的相关文献进行检索，搜集并整理有关地黄、梓醇抗骨质疏松方面的最新研究进展，归纳梓醇通过颅骨缺损模型、卵巢切除模型和糖尿病骨质疏松模型等体内动物模型和骨髓间充质干细胞、成骨细胞和破骨细胞等体外细胞模型发挥抗骨质疏松作用的实验结果，分析其研究动态、给药剂量、作用指标以及可能影响Wnt、Hedgehog和PTEN/RANKL等相关信号通路，挖掘潜在的作用靶点和分子机制，为更好地发挥、研究地黄和梓醇抗骨质疏松的作用及机制提供借鉴。     

High-magnitude mechanical strain inhibits the differentiation of bone-forming rat calvarial progenitor cells

Purpose: Orthodontic tooth movement occurs during the bone remodeling induced by therapeutic mechanical strain. It is important to investigate the relation between the strength of mechanical stress and bone formation activity. The aim of this study was to determine the effect of high-magnitude mechanical strain on bone formation in detail.

Materials and methods: Osteoblast-like cells isolated from fetal rat calvariae were loaded with 18% cyclic tension force (TF) for 48?h. To phenotypically investigate the effect of TF, we measured the number and the size of bone nodules stained by von Kossa technique on day 21 after cell seeding and determined the calcium content of bone nodules on day 14. Furthermore, we examined the gene expression of BMP-2, Runx2 and Msx2, which are important factors for bone nodule formation, on days 1, 4 and 7 after TF loading.

Results: The maximum bone nodule size in the control group was 1620 and 719?μm in the TF group. Furthermore, the mean number of bone nodules sized over 360?μm in the TF group was significantly decreased compared to the control group. The calcium content was also significantly decreased to 42% by TF loading. The mRNA expression of BMP-2, Runx2 and Msx2 was decreased 1 and 4 days after TF loading.

Conclusion: The differentiation of bone forming progenitor cells into bone nodule forming cells was inhibited by TF due to the decreased expression of bone formation related factors such as BMP-2, Runx2 and Msx2.     

Xanthohumol ameliorates 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin–induced cellular toxicity in cultured MC3T3‐E1 osteoblastic cells

2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is an environmental contaminant. Xanthohumol is a prenylated flavonoid found in hops (Humulus lupulus) and beer. The aim of the current study was to explore the role of xanthohumol in modulating the toxicity of TCDD in MC3T3‐E1 osteoblastic cells. In cells treated with TCDD alone, intracellular Ca²⁺ concentrations, mitochondrial membrane potential disruption, reactive oxygen species production, cardiolipin peroxidation, nitric oxide release and cytochrome P450 1A1 expression were significantly increased. TCDD treatment increased the mRNA levels of extracellular signal‐regulated kinase 1 and nuclear factor kappa B, and significantly decreased the level of protein kinase B (AKT) in MC3T3‐E1 osteoblastic cells. However, the presence of xanthohumol alleviated the pathological effects of TCDD. In addition, xanthohumol treatment significantly increased the expression of genes associated with osteoblast differentiation (alkaline phosphatase, osteocalcin, osteoprotegerin and osterix). We conclude that xanthohumol has a beneficial influence and may antagonize TCDD toxicity in osteoblastic cells.     

正交法优选愈骨葆方的最佳水提取工艺

采用正交试验方法研究愈骨葆方的最佳水提取工艺。通过血清药理学,以提取物对成骨细胞碱性磷酸酶(ALP)的活性的影响作为考察指标,采用L_9(3~4)正交表设计试验,对加水量(A)、加热时间(B)、浸泡时间(C)及煎煮次数(D)4个因素进行考察,分析最佳提取条件,并验证该工艺的有效性。通过该实验得出愈骨葆方最佳提取工艺:8倍加水量,加热时间60min,浸泡时间30 min,煎煮1次。按此工艺获得的愈骨葆方含药血清能显著地促进成骨相关基因的转录。该实验建立了愈骨葆方的最佳提取工艺,为该复方中药的开发利用提供了试验依据。     

大鼠下颌骨来源的成骨细胞对甲硝唑和替硝唑的转运

目的：应用SD大鼠下颔骨来源的原代成骨细胞，观察成骨细胞对甲硝唑和替硝唑的转运，探讨人工种植牙给药的影响及可行性。方法：将原代培养的新生鼠成骨细胞（newborn rat’s osteoblast，N）和成年鼠成骨细胞（adult rat’s osteoblast，A）与溶于PBS的药物共同孵育，分别于1，3，5，10min后，弃去细胞外液，收集各时间点细胞悬液，用高效液相色谱法测定细胞内药物量，用考马斯亮蓝法测定细胞蛋白总量。结果：（1）高效液相色谱法可以准确测定2种药物的量。（2）2种成骨细胞均可将甲硝唑和替硝唑转运至细胞内。结论：成骨细胞具有转运硝基眯唑类药物的能力，证实了人工种植牙给药的可行性。     

Nitric oxide promotes the progression of periapical lesion via inducing macrophage and osteoblast apoptosis

This study aimed to elucidate the modulation by nitric oxide (NO) of the apoptosis of macrophages and osteoblasts, the essential cellular components in the development of periapical lesions. Lipopolysaccharide (LPS) induced prominent nitrite synthesis in J774 mouse macrophage cell lines. Exposure to LPS induced obvious apoptosis in J774 cells, whereas transient transfection with murine inducible nitric oxide synthase (iNOS), small interfering RNA (siRNA) diminished this effect. Tumor necrosis factor-alpha (TNF-alpha) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) (a NO donor) triggered apoptosis in UMR-106 rat osteoblastic cell lines and a synergistic effect was noted when TNF-alpha and SNAP were added to the medium together. Administration of siRNAs for c-Fos and c-Jun: components of activator protein-1 (AP-1) and transforming growth factor-beta1 attenuated the combined effect markedly. Terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) stain in a rat model of induced periapical lesion showed positive apoptotic signals in macrophages and osteoblasts. Administration of N(G)-monomethyl-l-arginine markedly diminished the extent of bone loss and the amounts of apoptotic macrophages and osteoblasts. In conclusion, NO mediates LPS-stimulated apoptosis of macrophages. It also induces osteoblast apoptosis and augments the pro-apoptotic effect of cytokines. Inhibition of NO synthesis in vivo attenuates apoptosis and the size of periapical lesions. Taken together, these results suggest that NO may promote the progression of periapical lesion by inducing the apoptosis of macrophages and osteoblasts.     

兔骨髓基质细胞的体外成骨定向诱导培养

目的:体外分离培养兔骨髓基质细胞(bonemarrowstromalcells,BMSCs),并向成骨定向诱导培养,为骨组织工程提供适宜的种子细胞。方法:抽取新西兰白兔的骨髓,体外分离纯化得到BMSCs,并利用条件培养液将其向成骨定向诱导培养、扩增。采用倒置相差显微镜观察细胞增殖分化情况;使用碱性磷酸酶(ALP)和VonKossa染色的方法,鉴定其成骨性能;用MTT法描绘标准细胞浓度-OD值曲线。结果:BMSCs在培养皿中贴壁生长、增殖;经ALP和VonKossa染色证实其有成骨潜能;标准BMSCs细胞浓度-OD值曲线显示细胞浓度和OD值呈线性正相关。结论:可以通过在体外分离纯化骨髓并诱导培养,获得足够数量、有成骨潜能的BMSCs作为骨组织工程的种子细胞。