低强度脉冲超声对不同钛表面骨髓间充干细胞成骨分化的影响

目的:观察低强度脉冲超声(LIPUS)对大鼠骨髓间充质干细胞(BMSCs)在钛片表面成骨分化的影响.方法:将体外培养的BMSCs分别接种于光滑钛表面和大颗粒喷砂酸蚀(SLA)钛表面,进行矿化诱导并实施超声干预和假刺激.于矿化诱导后3、7d进行碱性磷酸酶(ALP)定量检测,14 d进行ALP染色观察;矿化诱导21 d后行茜素红染色;于矿化诱导14、21 d检测成骨相关基因及蛋白表达.结果:矿化诱导后3、7d超声组ALP活性较对照组高(P＜0.05),14 d超声组与对照组相比钛片表面ALP染色明显深染;茜素红染色显示,21 d后超声组的染色更明显且形成更多的矿化结节;超声组的成骨相关蛋白成骨转录因子2、骨形成蛋白、骨桥蛋白表达增高;RT-PCR检测到成骨相关基因、ALP、成骨转录因子2、骨形成蛋白、骨桥蛋白、骨钙素、Ⅰ型胶原蛋白均有不同程度表达增高(P＜0.05).结论:LIPUS可以促进光滑及SLA钛表面BMSCs的成骨分化.     

Runx2、Osterix转录因子过表达驱动内皮细胞成骨分化的机制探讨

目的:探讨Runx2和Osterix (OSX)过表达对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)成骨分化的调控作用.方法:通过慢病毒载体,将Runx2和Osterix基因分别转染入HUVECs.通过碱性磷酸酶(ALP)染色、半定量活性检测,探讨过表达Runx2和Osterix对HUVECs成骨分化的影响.通过RT-PCR、蛋白免疫印迹、免疫荧光染色检测成骨相关标志物Runx2、OSX、ALP、骨涎蛋白(BSP)、骨桥蛋白(OPN)、骨钙蛋白(OCN)在HUVECs中的表达.采用GraphPad Prism 6.01软件包对数据进行统计学分析.结果:Runx2过表达有利于HUVECs的成骨分化,而Osterix过表达则无此作用.HUVECs转染Runx2过表达慢病毒后,成骨相关基因Runx2、OSX、ALP、BSP、OPN及OCN的转录水平上调,同时Runx2、OSX、OPN及OCN的蛋白表达水平亦有所上调.结论:Runx2过表达可促进HUVECs的成骨分化.     

hBMP2修饰的β-TCP/胶原支架对MC3T3-E1细胞成骨能力的影响

目的:构建含hBMP2(human bone morphogenetic proteins 2)质粒DNA的β-TCP/胶原(β-tricalcium phosphate/collagen)支架材料,并研究其对MC3T3-E1细胞成骨能力的影响.方法:制备纳米级多孔β-TCP/胶原支架并负载含hBMP2目的DNA基因及对照质粒形成基因修饰的支架材料.建立MC3T3-E1细胞株与复合支架的体外培养体系.将其分为支架组hBMP2组(Z)对照质粒组(Z0),平皿hBMP2组(M)和对照质粒组(M0).复合培养后取样通过扫描电镜观察支架表面形态,成骨诱导1、3、7、14 d检测不同浓度BMP2支架组和非支架组细胞碱性磷酸酶(ALP)的活性,并在成骨诱导的不同时间点采用实时荧光定量PCR的方法检测Runx2、OCN、ALP、OPN等成骨相关标志基因表达.检测结果进行统计学分析.结果:含hBMP2为目的基因的质粒DNA修饰纳米β-TCP/Ⅰ型胶原溶液复合材料表面呈多孔样结构;支架组和平皿组中加入hBMP2质粒DNA都能提高ALP的活性以及成骨相关标志基因的表达;支架组对MC3T3-E1细胞成骨促进能力优于平皿组.结论:负载hBMP2基因修饰的β-TC P/胶原支架材料具有良好的骨诱导性.     

Behaviour of rat‐cultured dental pulp cells in three‐dimensional collagen type‐1 gel in vitro and in vivo

The purpose of this study was to investigate the growth and differentiation potential of dental pulp cells (DPCs) in three‐dimensional (3‐D) collagen type‐1 scaffold in vitro and in vivo. Third passage DPCs were cultured in a 3‐D collagen and expression of both bone‐ or dentin‐related mRNA (alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteopontin (OPN)) and morphological changes evaluated in vitro. In the in vivo study, two types of grafts were transplanted into the rectus abdominus muscles of rats and harvested after 7 days: DPCs in α‐minimal essential medium and DPCs mixed with a collagen gel. ALP, BSP and OPN were used as primary antibodies for immunohistochemical study. Histological and immunohistochemical results showed that DPCs in collagen gel were spindle shaped and showed significantly greater expression of ALP, BSP and OPN in vitro than the controls. Transplanted DPCs in collagen type‐1 gel showed greater positive immunoreactivity for ALP, BSP and OPN than the controls. It was concluded that the collagen gel scaffold encouraged the differentiation of DPCs into osteoblastic cells.     

p38信号通路参与调控上颌突间充质细胞的成骨分化

目的探索p38信号通路在上颌突间充质细胞体外成骨分化中的调控作用。方法取第1代E12.5 d的小鼠上颌突间充质细胞进行成骨诱导培养1周,实验组加入SB203580 （p38磷酸化抑制剂）。通过免疫荧光检测磷酸化p38的表达,通过Brdu标记和免疫荧光检测细胞的增殖能力,通过ALP染色和定量PCR检测成骨标志物的表达。采用SPSS18.0软件包对数据进行统计学分析。结果成骨诱导可促进上颌突间充质细胞中p38的磷酸化（p-p38）。抑制p38的磷酸化,可抑制上颌突间充质细胞增殖,降低成骨标志物ALP、Runx2、OCN和OPN的表达,使ALP染色减弱。结论p38信号通路参与调控体外培养的上颌突间充质细胞的成骨分化。     

高糖对人骨髓间充质干细胞成骨能力影响的体外研究

目的:体外模拟糖尿病病人高血糖状态,观察高糖对人骨髓间充质干细胞(human mesenchymal stem cells,hMSCs)成骨能力的影响。方法 :将使用不同含糖量培养液体外培养的hMSCs分为5.5mmol/L生理糖浓度组、25mmol/L高糖组、44 mmol/L高糖组。CCK-8试剂盒检测各组hMSCs的增殖速度;骨诱导7、14、21 d时分别观察高糖对hMSCs骨向分化相关基因骨钙素(OCN)、骨桥蛋白(OPN)、Runx相关因子2(Runx-2)的表达,碱性磷酸酶(ALP)活性,钙沉积量的影响。结果:两个高糖组相对生理糖组,有抑制hMSCs的增殖能力(P<0.05),且抑制ALP活性及细胞外钙基质沉积,下调了骨向分化相关基因OCN、OPN、Runx-2表达水平(P<0.01),该抑制作用随糖的浓度升高而加强。结论:高糖显著抑制了hMSCs生物矿化过程,并以浓度依赖的方式降低hMSCs的增殖及成骨能力。     

The osteogenic activity of human mandibular fracture haematoma-derived cells is stimulated by low-intensity pulsed ultrasound in vitro

Low intensity pulsed ultrasound (LIPUS) stimulation is a clinically established treatment method used to accelerate long bone fracture healing; however, this method is currently not applied to mandibular fractures. In this study, we investigated the effects of LIPUS on human mandibular fracture haematoma-derived cells (MHCs) in order to explore the possibility of applying LIPUS treatment to mandibular fractures. MHCs were isolated from five patients. The cells were divided into two groups: (1) LIPUS (+) group: MHCs cultured in osteogenic medium with LIPUS treatment; and (2) LIPUS (−) group: MHCs cultured in osteogenic medium without LIPUS treatment. The osteogenic differentiation potential and proliferation of the MHCs were compared between the two groups. The waveform used was equal to the wave conditions of a clinical fracture healing system. The gene expression levels of ALP, OC, Runx2, OSX, OPN, and PTH-R1 and mineralization were increased in the LIPUS (+) group compared to the LIPUS (−) group. There were no significant differences in cell proliferation between the two groups. These findings demonstrate the significant effects of LIPUS on the osteogenic differentiation of MHCs. This study provides significant evidence for the potential usefulness of the clinical application of LIPUS to accelerate mandibular fracture healing.     

犬骨髓基质干细胞诱导为成骨细胞的实验研究

目的：研究骨髓基质干细胞（Bone marrow stromal cells,BMSCs)在体外培养，诱导后的成骨活性，探讨BMSCs作为骨组织工程种子细胞的可能性和可行性。方法：抽取成年犬骨髓，用梯度离心法获取单核细胞，经条件培养液体外诱导培养后，进行组织化学、免疫组化、原位杂交检测，并在透射电镜下观察其成骨活性。结果：第1代细胞Alkaline phosphatase(AKP)染色、Core-binding factor alpha subunit 1(Osf2/Cbfal)、Osteopotin(OPN),I型胶原的免疫细胞化学检测和I型胶原的原位杂交结果开始呈现阳性，第3代细胞Bone Sailoplain(BSP),Osteocalcin(OCN)免疫细胞化学染色开始呈现阳性，透射电镜显示细胞外有胶原分泌和钙盐沉积。结论：BMSCs不仅能大量扩增，且在一定条件下可向成骨细胞分化，是骨组织工程理想的种子细胞。     

Extracellular matrix expression and periodontal wound-healing dynamics following guided tissue regeneration therapy in canine furcation defects

AIM: Temporal and spatial expression pattern of extracellular matrix (ECM) components in furcation defects following guided tissue regeneration (GTR) compared with open-flap debridement (OFD). MATERIAL AND METHODS: In 21 dogs, mandibular second and fourth pre-molars were treated with one non-resorbable and three different resorbable membranes. Third pre-molars were treated by OFD. After 2, 4, 8 weeks and 3, 6, and 12 months, tissues were analysed by immunohistochemistry for collagen I (Col-I) and III (Col-III), fibronectin (FN), bone sialoprotein (BSP), and osteopontin (OPN). RESULTS: At 2 weeks, the defect was mainly occupied by FN+ granulation tissue (GT), which was sequentially replaced by new connective tissue expressing FN, Col-I, and increasingly Col-III. Following superficial resorptions by OPN+ osteoclasts and odontoclasts, cementum and bone formation ensued with strong expression of BSP and OPN along bone and tooth surfaces. Deposition of Col-I, FN, BSP and OPN+ cementoid and osteoid became evident after 4 weeks. Extrinsic fibres of cementum and bone stained intensely for Col-III. The newly formed periodontal ligament expressed FN, Col-I, and Col-III, but no BSP or OPN. CONCLUSIONS: The spatial ECM expression was similar for OFD and the different GTR methods, although the timing and quantity of ECM expression were influenced by wound stabilization and inflammatory reactions.     

信号素3A对成牙骨质细胞系OCCM-30增殖和矿化功能影响的实验研究

目的:初步探讨信号素3A(Semaphorin3A, Sema3A)对成牙骨质细胞增殖、矿化的影响。方法:采用不同浓度的重组人Sema3A(0、0.5、1 mg/L)处理成牙骨质细胞OCCM-30。MTT法检测Sema3A对成牙骨质细胞增殖的影响,酶比活性法检测细胞碱性磷酸酶(ALP)活性的变化,实时荧光定量 PCR法检测骨钙素(OCN),骨桥蛋白(OPN)和Runx2基因的表达,茜素红染色法检测矿化结节的形成。结果:Sema3A对成牙骨质细胞的增殖和ALP活性无明显影响。Sema3A抑制OCN和Runx2基因的表达(P<0.05),并抑制矿化结节的形成。结论:Sema3A对成牙骨质细胞的增殖无明显影响,但对细胞的矿化功能起到抑制作用。     

骨形态发生蛋白7在高糖环境下对成骨细胞分化的影响

目的:研究对于重组人骨形态发生蛋白7(bone morphogenetic protein7,BMP7)在持续稳定高糖环境下对成骨细胞生物学性能及成骨活性的影响。方法:细胞取小鼠颅顶前成骨细胞亚克隆14(MC3T3-E1Subclone 14,MC3T3),分为4组:正常生理糖浓度组(葡萄糖浓度为5.5 mmol/L)为对照组,生理糖浓度+BMP7组高糖组(葡萄糖浓度为5.5 mmol/L,BMP7浓度为100 μg/L)(葡萄糖浓度为25 mmol/L),高糖+BMP7组(葡萄糖浓度为25 mmol/L,BMP7浓度为100 μg/L)。甲基噻唑基四唑(MTT)法检测不同条件培养后1 d、3 d、5 d、7 d后的细胞增殖情况,成骨诱导检测细胞碱性磷酸酶(alkaline phosphatase,ALP)活性。罗丹明-鬼笔环肽染色后以激光共聚焦显微镜观察MC3T3细胞骨架于BMP7作用24h后的形态变化,荧光实时定量PCR(quantitative real-time PCR,RT-qPCR)检测BMP7作用48 h后成骨基因特异性转录因子2(Runx2),骨钙素(osteocalcin,OCN)、碱性磷酸酶(ALP)的mRNA表达。结果:MTT实验显示25 mmol/L葡萄糖可抑制MC3T3增殖(P<0.05),加入BMP7后可提高细胞增值率(P<0.05)。并可上调高糖导致的ALP活性下降。细胞骨架观察结果显示,对照组细胞骨架成束状铺开,交织成网,较为均匀。高糖组细胞微丝解聚成团状,模糊不清。RT-qPCR结果显示BMP7可促进MC3T3细胞的ALP、OCN及Runx2(P<0.05)的表达。结论:持续稳定高糖环境能够抑制成骨细胞的增殖及ALP活性,影响细胞骨架结构,抑制成骨基因表达,添加BMP7可以在不同程度上反转该趋势,但仍较正常水平低。     

姜黄素通过调控Wnt通路改善牙周膜干细胞成骨分化能力

目的:探讨姜黄素对人牙周膜干细胞(PDLSCs)成骨分化的影响。方法:取第4~6代的PDLCs进行实验,用CCK-8实验检测姜黄素对PDLCs增殖活性影响,通过检测碱性磷酸酶(ALP)活性、矿化结节染色以及ALP、OCN和Runx2等成骨相关基因的表达水平来探讨姜黄素对牙周膜干细胞成骨分化能力的影响,同时检测姜黄素对经典Wnt通路及其配体的影响。结果:姜黄素对PDLSCs的增殖能力无影响。与对照组相比较,姜黄素能增加PDLSCs的ALP活性、上调ALP、OCN和Runx2等成骨相关基因的表达、增加矿化结节数量(P<0.05)。姜黄素能阻断Wnt信号通路,但加入Wnt信号通路激动剂(氯化锂)后,PDLSCs的成骨分化能力显著下降。结论:姜黄素能通过抑制Wnt信号通路,增强牙周膜干细胞成骨分化能力。     

miR-199a调控IGF1表达对机械刺激下成骨细胞分化的影响

目的： 探讨微小RNA（miR）-199a在机械牵张力刺激下MC3T3-E1细胞中的表达变化及其对牵张力刺激MC3T3-E1细胞成骨分化的作用机制。方法： 对体外培养的MC3T3-E1细胞加载12%牵张力0、3、6、12和24 h后,利用碱性磷酸酶（ALP）活性检测试剂盒检测ALP活性,实时荧光定量PCR检测骨钙素（OCN）、成骨细胞特异性转录因子Osterix（OSX）、Runt相关转录因子2（Runx2） mRNA和miR-199a的表达。将MC3T3-E1细胞分为对照组、牵张力组、牵张力+miR-NC组和牵张力+miR-199a组,加载12%牵张力和转染miR-199a模拟物后,观察miR-199a和OCN、OSX、Runx2 mRNA及蛋白表达以及ALP活性。茜素红S（ARS）染色观察钙结节形成能力。采用双荧光素酶报告基因实验检测miR-199a与胰岛素样生长因子1（IGF1）的靶向关系,实时荧光定量PCR法和免疫印迹法检测miR-199a模拟物对IGF1 mRNA和蛋白表达的影响。采用SPSS 24.0软件包对数据进行统计学分析。结果： 与0 h时间点相比,以机械牵张力刺激3、6、12和24 h后,MC3T3-E1细胞ALP活性和OCN、OSX、Runx2 mRNA表达水平均显著升高,而miR-199a表达水平显著降低（P<0.05）,12 h时变化最为显著。与对照组相比,牵张力组细胞中miR-199a表达水平显著降低,而细胞ALP活性、OCN、OSX、Runx2 mRNA及蛋白表达水平、钙结节形成水平均显著升高（P<0.05）;与牵张力组相比,牵张力+miR-NC组细胞中上述各指标差异均无统计学意义（P>0.05）;与牵张力+miR-NC组相比,牵张力+miR-199a组细胞中miR-199a表达水平显著升高,而细胞ALP活性、OCN、OSX、Runx2 mRNA及蛋白表达水平、钙结节形成水平均显著降低（P<0.05）。miR-199a可与IGF1靶向结合,miR-199a模拟物可使MC3T3-E1细胞中IGF1 mRNA和蛋白表达水平显著降低（P<0.05）。结论： miR-199a可抑制机械牵张力刺激诱导的MC3T3-E1细胞成骨分化,其作用机制可能与靶向调控IGF1表达有关。