Synergistic effects of Nell-1 and BMP-2 on the osteogenic differentiation of myoblasts.

Osteogenesis is synergistically enhanced by the combined effect of complimentary factors. This study showed that Nell-1 and BMP-2 synergistically enhanced osteogenic differentiation of myoblasts and phosphorylated the JNK MAPK pathway. The findings are important because of the osteochondral specificity of Nell-1 signaling and the potential therapeutic effects of coordinated BMP-2 and Nell-1 delivery. INTRODUCTION: BMPs play an important role in the migration and proliferation of mesenchymal cells and have a unique ability to alter the differentiation of mesenchymal cells toward chondrogenic and osteogenic lineages. Signaling upstream of Cbfa1/Runx2, BMPs effects are not limited to cells of the osteoblast lineage. Thus, additional osteoblast-specific factors that could synergize with BMP-2 would be advantageous for bone regeneration procedures. NELL-1 (NEL-like molecule-1; NEL [a protein strongly expressed in neural tissue encoding epidermal growth factor like domain]) is a novel growth factor believed to preferentially target cells committed to the osteochondral lineage. MATERIALS AND METHODS: C2C12 myoblasts were transduced with AdLacZ, AdNell-1, AdBMP-2, or AdNell-1+AdBMP-2 overexpression viruses. Effects were studied by cell morphology, alkaline phosphatase activity, osteopontin production, and MAPK signaling. Additionally, in a nude mouse model, viruses were injected into leg muscles, and new bone formation was examined after 2 and 8 wk. RESULTS: C2C12 myoblasts co-transduced with AdNell-1+AdBMP-2 showed a synergistic effect on osteogenic differentiation as detected by alkaline phosphatase activity and osteopontin production. Nell-1 stimulation on AdNell-1 + AdBMP-2 preconditioned C2C12 cells revealed significant activation of the non-BMP-2 associated c-Jun N-terminal kinase (JNK) MAPK signaling pathway, but not the p38 or extracellular signal-regulated kinase (ERK1/2) MAPK pathways. Importantly Nell-1 alone did not induce osteogenic differentiation of myoblasts. In a nude mouse model, injection of AdNell-1 alone stimulated no bone formation within muscle; however, injection of AdNell-1+AdBMP-2 stimulated a synergistic increase in bone formation compared with AdBMP-2 alone. CONCLUSIONS: These findings are important because of the confirmed osteochondral specificity of Nell-1 signaling and the potential therapeutic effects of enhanced BMP-2 action with coordinated Nell-1 delivery.     

去卵巢对大鼠颌骨成骨细胞增殖与成骨分化能力的影响

目的探讨去卵巢对大鼠颌骨成骨细胞增殖与成骨分化能力的影响。方法建立去卵巢大鼠骨质疏松模型,分离培养假手术组和去卵巢组颌骨成骨细胞并进行形态学观察。采用CCK-8法检测假手术组和去卵巢组大鼠颌骨成骨细胞的增殖能力差异。通过碱性磷酸酶染色与活性测定、矿化结节茜素红染色与定量、成骨相关基因及蛋白表达检测,探讨去卵巢对大鼠颌骨成骨细胞增殖及成骨分化能力的影响。结果假手术组和去卵巢组大鼠均可成功分离培养颌骨成骨细胞,两组细胞均可贴壁生长,细胞形态未见显著差异。与假手术组相比,去卵巢大鼠颌骨成骨细胞的增殖能力,碱性磷酸酶染色与活性均显著增高;但去卵巢大鼠颌骨成骨细胞的Runx2和OC在mRNA与蛋白水平的表达上及体外矿化结节形成能力方面皆显著低于假手术组。结论去卵巢可影响大鼠颌骨成骨细胞的增殖与成骨分化能力,研究结果将为探讨颌面部骨组织骨质疏松的发病机制与防治提供实验依据。     

血管内皮生长因子及其受体在鼠成骨细胞分化中的作用

目的 探讨血管内皮生长因子(VEGF)在鼠成骨细胞分化过程中的作用。方法 利用鼠原代FRC细胞培养系统(第0、5、9、14天)和取材新生鼠颅盖骨组织(5例)，采用反转录聚合酶链反应(RT．PCR)和免疫组织化学染色方法，检测VEGF及其受体Flt-1和KDR／Flk-1在FRC细胞分化、矿化过程中mRNA和在新生鼠颅盖骨组织中蛋白质的表达。结果 在控制培养条件下，FRC细胞出现明显的成骨特性。结合FRC细胞分化特性，RT-PCR检测发现VEGF及其受体Flt-1和KDR／Flk-1在FRC细胞中从分化到矿化过程中，mRNA表达逐渐增强。特别是在矿化后第9天和第14天表达水平明显增强。免疫组织化学染色证实了RT-PCR结果，新生鼠颅盖骨中的成骨细胞同时表达VEGF及其受体Flt-1和KDR／Flk-1。结论 VEGF及其受体Flt-1和KDR／Flk-1在成骨细胞分化和矿化过程中表达逐渐增强。作为一种重要的血管性因子，VEGF的自分泌作用方式在成骨细胞的分化中起重要作用。     

适宜电刺激对成骨细胞平面培养下细胞增殖分化及BMP-2表达的实验研究

目的:观察适宜电流刺激成骨细胞在平面培养下成骨细胞增殖及分化,明确是否具有促进增殖、分化作用,并观察电流刺激下BMP-2表达的变化。方法:将来自家兔幼仔颅骨提取的成骨细胞进行平面培养,2代之后进行分类培养,实验组进行电流刺激,并给予相同的刺激时间和刺激强度,对照组未进行电流刺激。之后在不同时间点进行细胞增殖、分化检测及BMP-2蛋白表达分析。结果:实验组8d内光镜下可见大量成骨细胞增殖,成骨细胞呈多形性改变,6～8d细胞内出现少量钙化点,而对照组骨细胞增殖缓慢。实验组分化明显,碱性磷酸酶及钙结节染色阳性,碱性磷酸酶定量分析显示逐渐增加。实验组经免疫组化分析显示BMP-2量逐渐增加。结论:电刺激可促进成骨细胞的增殖分化而达到实现细胞数目的短时间增加,细胞内部经过免疫组化染色后显示BMP-2表达增加。     

不同状态BMP-2对体外EMSCs成骨分化的作用

[目的]探讨骨形成蛋白(BMP-2)与组织型谷氨酰胺转氨酶(tTG, TG2)交联形成固化型和BMP-2游离型细胞生长因子,两种不同状态的BMP-2对鼻粘膜间充质干细胞(EMSCs)向成骨细胞分化的影响;[方法]体外培养、扩增并鉴定EMSCs;实验分四组:TG2+BMP-2、BMP-2、TG2和空白对照;四组细胞均采用定向成骨诱导培养基培养7 d;检测各组碱性磷酸酶活性及形成的钙结节面积大小;免疫印迹法检测成骨诱导相关蛋白表达水平;MTT法检测TG2、BMP-2和TG2+BMP-2对EMSCs增殖的影响。[结果]成骨诱导7 d后,TG2+BMP-2组细胞碱性磷酸酶活性较高,形成的钙结节较大,骨相关蛋白表达水平较高;TG2+BMP-2,TG2和BMP-2对EMSCs增殖能力无明显影响。[结论] TG2+BMP-2交联固化型细胞生长因子对EMSCs向成骨细胞分化表现出较强的促进作用,是组织工程化骨中理想的诱导成骨的细胞因子,具有广阔的应用前景。     

降钙素基因相关肽对大鼠成骨细胞增殖和分化的影响

目的 探讨外源性降钙素基因相关肽（CGRP）对大鼠颅盖骨来源成骨细胞的影响，以进一步了解CGRP促进成骨的作用机制。方法 利用二次酶消化法培养的成骨细胞，加入含不同浓度CGRP的条件培养液，24小时后通过MTT比色，^3H-TdR掺入以及细胞内碱性磷酸酶（ALP）含量的测定来观察CGRP对成骨细胞增殖和分化的影响。结果 CGRP可以明显促进成骨细胞增殖，而且作用呈剂量依赖性。CGRP对细胞内ALP含量无明显影响。结论 CGRP能够直接作用于成骨细胞并通过促进其增殖而有利于骨形成。     

山茱萸新苷Ⅰ对成骨细胞的增殖及成骨分化的影响

目的基于Wnt信号通路及内质网应激研究山茱萸新苷Ⅰ对大鼠原代成骨细胞的增殖及成骨分化的影响。方法提取原代成骨细胞,CKK8实验检测在药物浓度下山茱萸新苷Ⅰ对成骨细胞增殖的影响;碱性磷酸酶(alkaline phosphatase,ALP)染色检测不同浓度山茱萸新苷Ⅰ干预下成骨细胞ALP的活性情况; Real-time PCR检测Wnt2、β-catenin、BMP2、OPG、NOX4、PERK基因mRNA的表达; Western blot检测Wnt2、β-catenin、PDI、CHOP和BIP蛋白表达量。结果 CKK8实验及ALP染色表明山茱萸新苷Ⅰ对成骨细胞增殖及分化有一定影响,不同浓度山茱萸新苷Ⅰ干预下成骨细胞出现不同程度的增殖;与空白对照组相比,山茱萸新苷Ⅰ组的Wnt2、BMP2、β-catenin、OPG、NOX4的mRNA表达水平显著升高(P0. 01),而PERK明显降低(P0. 01)。与空白对照组相比,山茱萸新苷Ⅰ组的成骨细胞Wnt2、β-catenin、PDI蛋白表达量显著升高(P0. 01),CHOP表达亦有轻微上升,但不明显(P0. 05),而BIP的蛋白表达水平明显降低(P0. 01)。结论山茱萸新苷Ⅰ浓度为1 mmol/mL时在促进成骨细胞的增殖分化的作用上表现最佳,其能显著升高成骨细胞Wnt2、BMP2、β-catenin、OPG和NOX4的mRNA表达水平,而降低PERK的mRNA表达水平,升高Wnt2、β-catenin、PDI的蛋白表达量,降低BIP的表达量,在山茱萸新苷Ⅰ的干预下,Wnt信号通路及内质网应激途径对成骨活动的发生发展起着重要作用。     

Expression of BMP-2, TGF-beta, bFGF in guided bone regeneration

OBJECTIVE: To study the mechanism of guided bone regeneration combined with osteoinduction by observation of expression of BMP-2, TGF-beta, bFGF. METHODS: 42 adult, male, New Zealand rabbits were randomly divided into 6 groups, each group being 7 rabbits. 10mm standard bone defect model was produced bilaterally in the middle radial shaft of each rabbit. Randomly, one defect enveloped with silicon membrane was tested, and the other served as control, sacrificed at 3 days, 1, 2, 3, 4, 5 weeks after surgery for histological observation, immunohistochemical staining of BMP-2, TGF-beta, bFGF and in situ hybridization of their cDNA probes. RESULTS: Histologically bone defects was sealed by silicon membrane, in which inflammation tissue and callus were formed from cells in bone ends. Similar expression of BMP-2, TGF-beta, bFGF between the test groups and control groups was noted. Inflammatory cells in the hematoma expressed bFGF and proliferating periosteal cells, endosteal cells, medullary mesenchymal cells expressed TGF-beta at 3 days postoperatively. Osteocytes in the bone ends and osteoblasts lining callus surface started to express BMP-2, TGF-beta at first week after surgery. Following the formation of inflammation tissue, in which giant cells, macrophages, mesenchymal cells expressed TGF-beta, bFGF respectively. Although the expression of three osteoinductors was the same between the test and control sides, their content was very different in both sides. The whole content in all test sides was much more than all control sides (P < 0.01), the content of test side was also much more than control side in each group. CONCLUSIONS: It is a key reason for successful guided bone regeneration that membrane tube formed a relatively independent bone regenerative situation to prevent around tissue from interruption, and to prevent osteoinductors from diffusion, so that enhanced osteoinductors induced bone regeneration to repair bone defects.     

BMP-2信号通路与成骨细胞分化

骨形态发生蛋白(BMP)-2与多种细胞因子形成BMP-2信号通路,促进成骨细胞分化和骨细胞外基质合成与分泌,多种细胞因子则通过调节BMP-2信号通路影响骨代谢.该文就BMP-2两条重要信号通路BMP-2/Smads/Runx2/Osterix、BMP-2/Srnads/Msx2/Osterix与成骨细胞分化的近年研究进展作一综述.     

应力刺激对于后纵韧带骨化因子的影响

[目的]建立颈椎后路手术动物模型，增加后纵韧带的张力，检测后纵韧带中BMP-2及BMP-7的表达及水平，探讨机械应力刺激对后纵韧带骨化的作用机理。[方法]S-D大鼠100只，分为5组，每组20只，手术方式：（1）颈椎后路全椎板切除组；（2）颈椎后路全椎板切除＋肌肉切断组；（3）单纯椎旁肌止点切断组；（4）假手术组，仅作切口，剥离椎旁肌暴露；（5）对照组，不作任何处理。分别于术后1、2、4、8周，取实验动物手术节段后纵韧带标本，PCR方法检测BMP-2及BMP-7的表达水平。[结果]（1）颈椎手术后，全椎板切除＋肌肉切断组BMP-2，BMP-7水平上升最明显，与对照组比较有统计学差异；（2）颈椎后路全椎板切除组BMP-2，BMP-7水平水平上升，与对照组比较有统计学差异；（3）单纯椎旁肌止点切断组BMP@，BMP-7水平上升，与对照组比较有统计学差异；（4）假手术组BMP-2，BMP-7水平与对照组比较无明显变化。[结论]手术导致的机械刺激提高BMP-2，BMP-7在大鼠后纵韧带内的表达水平；认为虽然动物模型不能完全模拟人体情况，但是BMP-2，BMP-7在OPLL的早期可能具有始动作用，而BMP-7在后续的骨化过程中可能继续发挥作用。建议临床手术时应尽量采取微创，减少术后不稳增加后纵韧带的应力。     

血管内皮生长因子在人类和鼠成骨细胞中的选择性剪接表达

目的 探讨血管内皮生长因子(VEGF)各种转录本亚型在成骨细胞分化中的作用。方法应用特殊设计的引物，逆转录．聚合酶链反应(RT-PCR)检测VEGF mRNA在人类成骨细胞样细胞SaOS-2和MG63和胎鼠颅盖骨细胞(FRC)在第0、5、9、14天不同分化阶段中的选择性剪接表达。结果 人类成骨细胞样细胞SaOS-2和MG63表达所有的VEGFmRNA亚型，其中以VEGF121和VEGFl65表达最强。鼠FRC细胞表达3种VEGF mRNA亚型(即VEGF120，VEGFl44和VEGF 164)，其中以VEGF120和VEGF164表达最强。伴随着FRC细胞的增殖、分化和矿化，这些亚型的表达逐渐增强，并且在结节矿化后达到最高水平。结论小分子的’EGF121／120和VEGF165／164在成骨细胞的分化过程中表达增强，可能起重要的血管源性调节作用。     

Synergistic effect of Wnt modulatory small molecules and an osteoinductive ceramic on C2C12 cell osteogenic differentiation

Although osteoinductive ceramics can induce osteoblast differentiation in vitro and bone regeneration in vivo, their effects rely solely on the limited number of endogenous stem cells. More recently, ceramic carriers seeded with culture-expanded stem cells have been reported as implants capable of in vivo bone formation. However, effective and safe signaling agents that promote cell differentiation to the osteogenic lineage are still needed. In the present report, two osteogenic small-molecules THQ-1a and PP-9 were identified by testing a series of compounds for Runx2 and BMP2 expression in C2C12 cells. Compounds THQ-1a and PP-9 modulated Wnt signaling and enhanced the expression of molecular markers of osteoblast differentiation. To probe the utility of these compounds for use with ceramic cell implants, the effect of THQ-1a and PP-9 on C2C12 cell osteogenic differentiation was investigated in the presence of a tricalcium phosphate (TCP) ceramic. The effect of THQ-1a and PP-9 on markers such as Osteocalcin and Collagen I was significantly increased in the presence of TCP ceramic. Additionally, THQ-1a or PP-9 in the presence of TCP ceramic gave a synergistic increase in alkaline phosphatase activity in the differentiation of C2C12 cells. Taken together, the results suggest an approach to directing cell lineage commitment for bone regeneration by the application of small-molecule osteogenic agents to cells in the presence of osteoinductive ceramics.     

乳铁蛋白对大鼠成骨细胞增殖与分化的影响

目的观察乳铁蛋白(Lf)对大鼠成骨细胞增殖分化的影响,初步探讨Lf对成骨细胞的作用机制。方法用不同浓度的Lf干预成骨细胞,在不同时间分别测定细胞数目的增殖、细胞内碱性磷酸酶活性,并用半定量RT-PCR法检测成骨细胞内RANKL/OPG mRNA基因的表达。结果Lf呈时间和浓度依赖性地促进大鼠成骨细胞增殖及碱性磷酸酶活性,每组实验在不同时间的差异均有显著的统计学意义(P<0.05),其中400μg/ml组在72h时细胞增殖数目达到最大。在碱性磷酸酶活性方面,400μg/ml组在72h时则有所下降。不同浓度Lf、不同作用时间均能促使成骨细胞中OPG mRNA表达增加,同时抑制RANKL mRNA表达。结论Lf能促进成骨细胞的增殖分化,并且能够调节成骨细胞RANKL/ OPG mRNA表达,从而抑制破骨细胞介导的骨吸收。     

骨形成蛋白-2诱导脊髓神经干细胞分化的实验研究

目的：研究不同浓度的骨形成蛋白-2(bone norphogenetic protein-2，BMP-2)对脊髓源性神经干细胞(neural stem cells，NSCs)诱导分化成为神经细胞(神经元和神经胶质细胞)的影响。方法：取孕14d的胚胎小鼠脊髓，原代培养出脊髓NSCs。培养四代后，分别在碱性成纤维细胞生长因子(bFGF)存在与否的不同条件下，加入不同浓度的BMP-2．观察细胞的增殖、分化情况，用免疫组织化学的方法进行鉴定，并进行统计学分析：结果：低浓度的BMP-2(1～10ng／ml)与bFGF(20ng／ml)联合作用，可促进脊髓NSCs向神经元和星形胶质细胞分化，抑制其向少突胶质细胞分化。较高浓度BMP-2(100ng／ml)可抑制脊髓NSCs的增殖甚至导致细胞死亡。结论：脊髓NSCs在低浓度BMP和bFGF联合作用下能有效地分化成具有多种特性的神经样细胞，并与脊髓具有良好的同源性，可为脊髓损伤的修复研究提供良好的细胞学基础。     

MMP-2、TIMP-2、VEGF和bFGF在血管瘤增生及消退过程中的变化

目的 探讨基质金属蛋白酶-2（MMP-2）及其抑制剂（TIMP-2）、血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）在血管瘤增生、消退过程中的变化。方法 采用免疫组织化学链霉亲和素-过氧化酶（SP）法，检测增生期血管瘤32例、消退期血管瘤10例、血管畸形17例及小儿正常皮肤10例标本中MMP-2、TIMP-2、VEGF及bFGF的表达。结果 MMP-2、VEGF及bFGF在增生期血管瘤中的表达明显高于消退期血管瘤、血管畸形和正常皮肤，其差异有统计学意义；TIMP-2在消退期血管瘤中的表达明显高于增生期血管瘤、血管畸形和正常皮肤，其差异有统计学意义。结论 MMP-2、VEGF及bFGF可能促进血管瘤血管生成，从而促进血管瘤增生，而TIMP-2可能促进血管瘤消退。     

Laser and LED photobiomodulation effects in osteogenic or regular medium on rat calvaria osteoblasts obtained by newly forming bone technique

Lasers in Medical Science - The purposes of this study are to evaluate the effects of photobiomodulation (PBM) with laser and LED on rat calvaria osteoblasts (rGO lineage), cultured in osteogenic...     

血管内皮生长因子及骨形态发生蛋白2对成骨细胞生长的促进作用

目的研究血管内皮生长因子（vascular endothelial growth factor,VEGF）以及骨形态发生蛋白2（bone morphogendtic protein 2,BMP-2）对成骨细胞增殖的调节作用。方法提取人骨髓间充质干细胞（mesenchymal stem cells,MSCs）并使其分化为成骨细胞,分别添加不同浓度的VEGF和BMP-2进行药物干预,用四甲基偶氮唑盐（MTT）法研究成骨细胞的增殖率。结果两组干预组的吸光度（A）值与对照组的A值相比较,差异有统计学意义（P〈0.05）,对成骨细胞增殖的调节作用均随剂量和时间变化而改变,两组调节作用的最佳时间均为72 h左右。两组最佳作用浓度分别为：BMP-2为1.8×10-9 mol/L,对成骨细胞的增殖率达179.59%;VEGF为1×10^-8 mol/L,其增殖率达189.80%。结论 VEGF对成骨细胞增殖的促进作用不亚于BMP-2。     

血清素对体外培养大鼠成骨细胞增殖分化和矿化功能的影响

目的 探讨不同浓度血清素对体外培养大鼠成骨细胞(OBs)增殖、分化和矿化功能的影响. 方法 在新生SD大鼠颅骨OBs培养液中分别加入不同浓度血清素:0 mol/L组(空白对照组)、10-9 mol/L组、10-8 mol/L组、10-7 mol/L组、10-6 mol/L组、10-5 mol/L组,观察不同浓度血清素对OBs的增殖能力(CCK-8法)、分化能力(Western法检测碱性磷酸酶蛋白水平、pNPP法检测碱性磷酸酶活性和ELISA法检测骨钙素蛋白表达水平)和矿化能力(茜素红染色)的影响.并用荧光定量聚合酶链反应方法检测OBs分化早、晚期血清素受体亚型的mRNA表达水平. 结果 不同浓度血清素均可抑制OBs的增殖、分化和矿化,这种抑制作用在低浓度时具有时间依赖性,而在高浓度时作用减弱,呈现“V”形趋势.5-HT1A、5-HT1B、5-HT1D、5-HT2A、5-HT2B、5-HT2C等受体在OBs上均有表达,其中5-HT2A和5-HT1B受体是表达最多的两种受体亚型. 结论 体外OBs表达血清素受体,血清素可抑制OBs的增殖、分化和矿化,提示血清素能够调节骨代谢.     

Follistatin 表达抑制促进 BMP-2诱导人类骨髓间充质干细胞成骨分化的实验研究

目的探讨Follistatin表达抑制对人类骨髓间充质干细胞（BMSC）细胞活性及骨形态发生蛋白（BMP）‐2诱导人类BMSC成骨分化的影响。方法采用 Follistatin特异性 siRNA 转染人类BMSC ,检测线粒体脱氢酶活性、细胞DNA含量及蛋白含量。采用定量逆转录‐聚合酶链式反应（qRT‐PCR）检测成骨相关基因表达,采用碱性磷酸酶（ALP）染色和茜素红染色检测 Follistatin对BMP‐2诱导人类BMSC成骨分化的影响。结果转染后3、7 d ,人类BMSC代谢、DNA含量显著升高;转染后14 d ,总蛋白含量增加。Follistatin表达抑制后成骨相关基因如ALP、OCN、OSX、OC、OPN、RUNX2等表达升高,且ALP活性及钙沉积量显著增加。结论抑制Follistatin表达可促进人类BMSC细胞活性和BMP‐2诱导人类BMSC成骨分化能力,Follistatin可抑制人类BMSC成骨分化。