细胞外基质磷酸糖蛋白在大鼠牙周组织缺损愈合过程中的表达

24只成年健康雄性Wistar大鼠随机分2组:术后14d组和术后28d组各12只,行左侧下颌骨开窗术,制备牙周组织缺损模型,HE染色观察牙周组织缺损愈合情况,免疫组织化学染色法观察MEPE在牙周组织缺损愈合过程中各组织的表达。结果:术后14d,术区有部分新生牙槽骨形成,部分牙周纤维附着于根面牙本质上;术后28d,术区完全被新生牙槽骨覆盖,在新生牙槽骨和牙本质之间可见牙     

细胞外基质磷酸糖蛋白在小鼠牙齿发育过程中的表达

目的:观察细胞外基质磷酸糖蛋白(MEPE)在小鼠牙齿发育过程中牙胚和牙周组织中的表达变化,初步探讨MEPE在小鼠牙齿发育过程中可能发生的作用.方法:免疫组织化学染色法观察MEPE在小鼠牙齿发育过程中牙胚和牙周组织的表达变化.结果:牙胚发育早期,MEPE在成釉细胞、成牙本质细胞和牙髓组织中均有表达.随着牙胚的发育,MEPE在上述细胞中的表达逐步减弱,在牙周膜中逐渐表达.在前期牙本质中表达.牙胚发育完成后,MEPE在牙周膜,特别是成熟牙槽骨骨陷窝中的骨细胞中呈现高表达.结论:细胞外基质磷酸糖蛋白可能在牙齿硬组织形成、牙周膜的形成和稳定等方面发挥重要作用.     

细胞外基质磷酸化糖蛋白mRNA在人牙周韧带细胞成骨分化过程中的表达

目的 检测人牙周韧带细胞(periodontal ligament stem cell,PDLC)诱导矿化过程中碱性磷酸酶(alkaline phosphatase,ALP)、骨钙素(osteocalcin,OCN)和细胞外基质磷酸化糖蛋白(matrix extracellular phosphoglycoprotein,MEPE)mRNA的表达,探讨MEPE能否作为人牙周韧带细胞的分化标记及其功能.方法 酶消化法培养PDLC并鉴定其来源,取未诱导及矿化诱导7、14和21 d的PDLC,茜素红染色检测矿化结节的形成;免疫组织化学染色检测OCN的表达;实时荧光定量反转录聚合酶链反应(RT-PCR)检测ALP、OCN和MEPE mRNA的表达变化,并对结果进行方差分析.结果 PDLC矿化诱导后茜素红染色显示钙化结节形成,免疫染色OCN表达增强;PDLC成骨诱导培养前ALP、OCN和MEPE mRNA表达系数分别为72、1.1和534.随着诱导时间延长,ALP、OCN和MEPE mRNA表达上调,诱导7 d组的表达系数分别为78、9.56和629.6,诱导14 d组的表达系数分别为290、133和638.3,诱导21 d组的表达系数分别为1108、925和2261.1.与对照组相比,各诱导组OCNmRNA的表达、诱导14 d和21 d组ALP mRNA的表达,以及诱导21 d组MEPE mRNA的表达,差异均有统计学意义(P<0.05).结论 在PDLC向成牙骨质或成骨样细胞分化过程中,MEPE mRNA与ALP和OCN呈现相似的表达变化趋势,提示MEPE与PDLC成骨分化有关,有可能作为PDLC向成牙骨质或成骨样细胞分化的标志.     

细胞外基质磷酸糖蛋白及其重要的结构片段

细胞外基质磷酸糖蛋白(MEPE)是一种细胞外基质的非胶原性磷酸化糖蛋白,主要表达于骨组织、牙组织和肾近球小管中,在骨形成矿化以及调节磷吸收方面发挥重要作用.酸性丝氨酸-天冬氨酸-富集细胞外基质磷酸糖蛋白相关性基序与细胞外基质磷酸糖蛋白活性片段/AC-100多肽是MEPE的重要结构域,其生物学功能是近来研究的热点.     

细胞外基质磷酸糖蛋白在牙齿组织中的表达

目的 细胞外基质磷酸糖蛋白(matrix extracellular phosphoglycoprotein,MEPE)是新近在骨和牙齿组织中发现的蛋白.检测MEPE在牙齿组织中的表达以及随着组织分化MEPE表达的变化.方法 通过免疫组化染色对MEPE蛋白在人牙胚中的表达进行初步定位.分别分离培养人的牙髓细胞和成釉器上皮细胞,应用半定量PCR技术探讨MEPE在这两种细胞中的时序表达变化.结果 MEPE在成釉细胞、牙髓和成牙本质细胞中均有表达.MEPE的表达随着牙髓细胞的分化而逐渐下调.随着成釉器上皮细胞培养代次的增加,MEPE表达逐渐下降.结论 MEPE的下调提示MEPE可能在牙齿硬组织的形成过程中起到调控作用.     

细胞外基质磷酸化糖蛋白在人牙髓细胞成牙本质分化中的表达

义(P<0.05).蛋白质印迹法检测显示各矿化标记的蛋白表达均较对照组上调.结论 在hDPC诱导成牙本质分化的过程中,MEPE与DSPP、DSP、BSP、Ⅰ型胶原呈现相似的表达变化趋势,提示MEPE与hDPC的成牙本质分化有关,可作为hDPC向成牙本质样细胞分化的标志.     

重组人细胞外基质磷酸化糖蛋白（MEPE）对牙髓细胞碱性磷酸酶活性的影响

目的：通过构建细胞外基质磷酸化糖蛋白的原核表达质粒并在大肠杆菌中诱导成釉蛋白的全长表达并进行纯化,观察MEPE对人牙髓细胞增殖和碱性磷酸酶活性的影响,从而了解该蛋白在牙齿发育过程中的作用。方法：使用人脑cDNA文库克隆MEPE基因并进行序列分析。在大肠杆菌中表达细胞外基质磷酸化糖蛋白,并纯化和分析。检测重组人细胞外基质磷酸化糖蛋白对牙髓细胞碱性磷酸酶活性的影响。结果：重组人细胞外基质磷酸化糖蛋白可提高牙髓细胞的ALP活性水平（P〈0．05）。结论：MEPE可提高牙髓细胞的ALP活性水平,为MEPE在临床上对生活牙髓的保存治疗和组织工程化牙本质修复牙体组织缺损提供理论基础。     

工程化基质在牙周组织再生中的临床应用

"工程化基质"是用组织工程学的方法构建的细胞外基质,是种子细胞赖以生长的周围环境。本文就近几年来,工程化基质在牙周组织再生中的研究、应用进展,作一综述。     

细胞外基质磷酸化糖蛋白的研究现状

细胞外基质磷酸化糖蛋白(MEPE)定位于人类染色体4q21.1.由于MEPE在肿瘤相关性低磷性骨软化患者(OHO)的肿瘤组织中高表达,故其被认为是导致低磷性骨软化的调磷因子.MEPE主要表达于分化成熟的成骨细胞和骨细胞中,具有抑制骨形成和矿化的作用,是一种矿化抑制因子.在牙齿组织中,MEPE主要表达于成牙本质细胞,并与多种致病基因位于染色体4q21上的牙体硬组织疾病如釉质发育不全、Ⅱ和Ⅲ型牙本质发育不全有关.     

基质金属蛋白酶与牙周膜细胞外基质代谢

基质金属蛋白酶在牙周膜细胞外基质代谢过程中发挥着关键性的调节作用，而牙周膜细胞外基质降解与合成的平衡是牙周组织改建的物质基础。本文就基质金属蛋白酶的一般特性、活性调节及对牙周膜细胞外基质代谢的影响进行了综述。     

An immunohistochemical study of matrix molecules associated with barrier membrane-mediated periodontal wound healing

Guided tissue regeneration (GTR) is a clinical procedure developed to facilitate periodontal regeneration by using barrier membranes to selectively promote the repopulation of a periodontal defect by periodontal ligament and bone cells at the expense of epithelial and gingival connective tissue cells. The aim of this study was to gain insight into the biological events occurring during membrane mediated periodontal wound healing by examining the immunohistochemical expression of a number of extracellular matrix components in tissues treated via the GTR technique. Experimental periodontal defects were created around the second premolar tooth in 4 dogs and wound closure was achieved by application of expanded polytetrafluoroethylene membranes around each tooth and flap positioning coronal to the cementoenamel junction. The dogs were sacrificed after a 4-wk healing period, block dissections of the part of the mandible containing the experimental tooth were obtained and paraffin sections were prepared. Using standard immunohistochemical techniques, the sections were stained with a monoclonal antibody against bone morphogenetic proteins 2 and 4 (BMP-2 and -4) and polyclonal antibodies against collagen I, collagen II, decorin, biglycan, bone sialoprotein, osteopontin and osteocalcin. Collagen I was predominantly localized within the regenerating bone, whereas collagen III staining was more abundant in the soft connective tissues of the defect. Decorin and biglycan staining was faint within the extracellular matrix of the regenerating defect, although both proteoglycans exhibited intense intracellular localization within some of the cells inhabiting the defect. The staining for BMP-2 and -4 was weak within the bone but strong within the extracellular matrix of the regenerating soft tissue. Osteopontin and bone sialoprotein were strongly localized in the regenerating bone and cementum found within the defect. Osteocalcin staining was present in both the regenerating and mature cementum and associated cementoblasts, and it was relatively weaker in the regenerating bone compared to the mature bone. The observed pattern of immunolocalization of the extracellular matrix macromolecules suggests that the heterogeneous cell population filling the GTR wound had created an environment that was conducive to periodontal regeneration.     

Mineralized tissue-formation in periodontal wound healing

The purpose of the present study was to examine and compare the different mineralized tissues that are found on and around the dental root following treatment of different periodontal pathosis. The material has been compiled from previously published experimental studies on periodontal therapies and trauma treatments. 4 distinctly different appearances of the mineralized tissue layers on the marginal dentin surfaces were described; new cementum, non-attached bone-like tissue, partly attached bone-like tissue and ankylosis preceded by root resorption. It was concluded that, healing in the periodontal/root interface following periodontal therapy may yield different mineralized tissues, depending on a number of host-specific and external factors. The temporal pattern of such healing processes is schematically represented.     

Potentials for root resorption during periodontal wound healing

The present study was undertaken to examine whether (1) the process of resorption, which invariably affects periodontitis involved reimplanted roots facing bone or gingival connective tissue during healing, is a transient phenomenon and, (2) root resorption can be prevented by permitting downgrowth of epithelium along the root surface. A total of 24 teeth in 2 monkeys (Macaca cynomolgus) was subjected to experimental periodontal tissue breakdown by the placement of elastic ligatures around the teeth. The ligatures were left in situ until about 50% of the supporting tissues had been lost. Following removal of the ligatures, the teeth were extracted and the denuded portions of the roots were scaled and planed. The crowns of the teeth were resected and the root canals filled with guttapercha. The roots were subsequently implanted into sockets prepared in the jaw bone in such a way that each root was embedded in bone except for a portion which was in contact with gingival connective tissue. 1 month prior to sacrifice of the animals, the cut surface of the coronal part of the roots was exposed by removal of the covering soft tissue. The epithelium was thereby allowed to migrate into the wound. Implantation of the roots was scheduled to provide healing periods of 1, 2, 3, 4, 8, 12, 16, 20 and 24 weeks before exposure of the roots. The histologic examination of the implant specimens disclosed that replacement resorption was a progressive process which eventually resulted in the elimination of the transplanted roots. It was possible to prevent root resorption in this model by permitting apical downgrowth of epithelium along the root surface during the initial phase of healing. The results are discussed in relation to procedures used in periodontal therapy.     

低能量激光治疗在牙周组织愈合中的作用

近年来激光在口腔医学领域的应用日益广泛。在牙周治疗中,激光可用来进行牙结石去除、根面处理、软组织及骨修整等,参与到牙周治疗的各个环节,起到很好的辅助牙周治疗作用。低能量激光是指能量较温和、治疗时不产生热量的一类激光。在牙周治疗时可利用其生物刺激功能起到抑制牙周炎症、促进创口愈合及牙周组织再生等方面的作用。文章主要介绍低能量激光的特点、作用机制及临床使用方法,为低能量激光治疗在临床的进一步推广应用提供思路。     

Cellular reactions in pulpal and periodontal tissues after periodontal wound debridement

Periodontal wounds in monkeys were prepared with a bur followed by the application of microbially contaminated cotton pellets. 3 weeks later, the wounds were debrided by scaling followed by etching with citric acid or by treatment with carbonate/peroxidate. The cellular reactions in the periodontal tissues and in the pulp 4, 11, 25, 39 and 53 days after treatment were followed with light microscopy. The marginal periodontium showed heavy inflammatory reactions immediately after treatment, regardless of the debridement procedure. 25 days after debridement, a long epithelial junction had been formed. The apical part of the epithelium deviated from the root surface into the connective tissue, delineating a heavily inflamed part of the connective tissue. After 39 to 53 days, most of the experimental wounds were covered by an epithelial lining. The pulpal reactions were generally limited to a production of irregular dentin on the pulpal wall facing the periodontal wound. It was concluded that the marginal healing pattern following various chemical treatments to the root surface followed, in all essential aspects, conventional treatment with scaling and root planing.     

Effect of cigarette smoking on periodontal healing following GTR in infrabony defects

Abstract This retrospective study examined the effect of cigarette smoking on the healing response following guided tissue regeneration (GTR) in deep infrabony defects. 71 defects in 51 patients underwent GTR with teflon membranes. 20 patients (32 defects) smoked more than 10 cigarettes per day, while 31 patients (39 defects) did not smoke. Clinical measurements were available at baseline, at membrane removal and at the 1-year follow-up. The oral hygiene of both groups was good, but smokers had significantly higher full mouth plaque scores. No significant differences were observed between smokers and non-smokers in terms of % of tissue gained at membrane removal. At the 1-year follow up, however, smokers gained significantly less probing attachment level than non-smokers (2.1 ± 1.2 mm compared with 5.2 ± 1.9 mm). A multivariate model, correcting for the oral hygiene level of the patients and the depth of the infrabony component, indicated that smoking was in itself a significant factor in determining the clinical outcome. A risk-assessment analysis indicated that smokers had a significantly greater risk than non-smokers to display a reduced probing attachment level gain following GTR. It is concluded that cigarette smoking is associated with a reduced healing response after GTR treatment, and may be responsible, at least in part, for the observed results.     

血管新生理论在牙周创面愈合中的应用前景

血管新生在牙周创面愈合和组织再生中有着重要作用,是牙周组织再生技术必须依赖的基础。本文就血管新生理论在牙周创面愈合中的应用情况进行综述,以期对牙周组织再生治疗有所裨益。