尼古丁对大鼠牙槽骨内ALP和DMP1 C末端表达的影响

目的:观察尼古丁对大鼠牙槽骨内碱性磷酸酶(ALP)和牙本质基质蛋白1(DMP1)C末端表达的影响. 方法:将20只5周龄健康雄性Wistar大鼠随机等分为实验组和对照组,每组再随机等分为30天和60天两个亚组,实验组每天腹腔注射尼古丁0.73 mg·kg-1. 分别使用钙钴法和免疫组化法检测ALP和DMP1 C末端在大鼠牙槽骨内的表达. 结果: 对照组:ALP和DMP1 C末端都为深棕色线形表达于牙槽骨的钙化前缘, 形成明显的矿化条带;ALP和DMP1 C末端分别为棕色沉淀和棕黄色颗粒状密布于骨细胞周围.实验组:ALP和DMP1 C末端表达部位同对照组,表达强度减弱;相对于30天组,60天组变化更明显. 结论:尼古丁可能通过抑制大鼠牙槽骨内ALP和DMP1 C末端的表达,抑制大鼠牙槽骨的矿化.     

环孢素 A 对大鼠牙槽骨内 DMP1 C 末端和 OPN 表达的影响

目的：观察环孢素A（cyclosporinA,CsA）对大鼠牙槽骨内牙本质基质蛋白1（dentinmatrixprotein,DMP1）C末端和骨桥蛋白（osteopontin,OPN）表达的影响。方法：30只7周龄健康雄性Wistar大鼠,随机等分为对照组和实验组,每组再随机等分为20d、30d和40d3个亚组,实验组大鼠喂饲CsA（30mg／k·d）。免疫组化法染色下颌第一磨牙颊舌向石蜡切片,光镜下观察DMP1C末端和OPN在牙槽骨内的表达情况。结果：与对照组大鼠比较,实验组大鼠牙槽骨内DMP1C末端表达明显下调,OPN表达明显上调;在本实验周期内,上述变化随实验时间的延长而加重。结论：CsA影响大鼠牙槽骨内矿化相关非胶原蛋白DMP1C末端和OPN的表达,推测CsA可能抑制大鼠牙槽骨的矿化。     

二膦酸盐对骨质疏松大鼠下颌牙槽骨牙本质基质蛋白1表达的影响

目的 :观察二膦酸盐对去卵巢骨质疏松大鼠下颌牙槽骨内破骨细胞以及牙本质基质蛋白1(dentin matrix protein1,DMP1)表达的影响。方法 :取6月龄SD大鼠30只,随机分为假手术组(Sham)、去卵巢模型组(OVX)和二膦酸盐药物治疗组(RIS),每组10只。Sham组大鼠仅术中暴露卵巢不切除,OVX组大鼠行"双侧卵巢切除术+生理盐水皮下注射",RIS组行"双侧卵巢切除术+利塞磷酸钠(2.4μg/kg)皮下注射"。术后3个月取各组大鼠下颌骨常规脱钙,甲苯胺兰染色观察下颌第一磨牙(M1)区域牙槽骨组织学结构,抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)染色观察M1区域牙槽纵隔破骨细胞的骨吸收情况,免疫组化染色观察各组M1牙槽骨DMP1分布表达情况,并进行相关半定量图像分析。结果:与Sham组相比,OVX组TRAP阳性细胞数增加;而较OVX组而言,RIS组TRAP阳性细胞数显著减少(P<0.05)。免疫组化染色显示,各组DMP1不仅表达在牙槽骨骨细胞内,牙槽间隔的松质骨骨基质、牙周韧带中均可见其表达,OVX组M1牙槽骨DMP1表达较Sham组减少(P<0.05),而RIS组表达较OVX组有升高。结论:二膦酸盐能减少骨质疏松大鼠下颌牙槽骨破骨细胞数量,并上调DMP1表达,从而影响下颌牙槽骨矿化。     

被动吸烟对大鼠牙槽骨内DSP和OPN表达的影响

目的:观察被动吸烟对大鼠牙槽骨内牙本质涎蛋白(dentin sialoprotein,DSP)及骨桥蛋白(osteopontin,OPN)表达的影响。方法:20只6周龄健康雄性Wistar大鼠随机等分为对照组和实验组,每个大组再等分为30d和60d两个亚组。采用单纯烟熏法建立大鼠被动吸烟模型,免疫组织化学法检测DSP和OPN在大鼠牙槽骨内的表达。结果:与对照组大鼠相比较,实验组大鼠牙槽骨内DSP和OPN表达均明显上调;在本实验周期内,上述变化随实验时间的延长而加重。结论:被动吸烟上调大鼠牙槽骨内矿化相关非胶原蛋白DSP及OPN的表达,推测DSP和OPN在被动吸烟抑制牙槽骨矿化的发病机制中发挥一定的作用。     

高迁移率族蛋白B1在人牙髓细胞成牙本质分化中的表达

目的:检测人牙髓细胞(human dental pulp cells,hDPCs)诱导矿化过程中高迁移率族蛋白B1(high-mobility group box 1,HMGB1)的表达变化,探讨HMGB1在人牙髓细胞损伤修复中的可能作用。方法:组织块法分离培养hDPCs,收集矿化诱导0、3、7、11、14d后hDPCs的mRNA、蛋白质及细胞爬片,实时荧光定量反转录聚合酶链反应(RT-PCR)和蛋白质印迹法(western blot)分别检测HMGB1、牙本质涎磷蛋白(dentin sialophosphoprotein, DSPP)、牙本质基质蛋白1(dentin matrix protein 1, DMP1)及碱性磷酸酶(alkaline phosphatase, ALP)的mRNA及蛋白表达水平;并检测ALP活性,免疫荧光检测HMGB1在hDPCs矿化过程中的表达。结果:hDPCs矿化诱导后,DMP1、DSPP、ALP及HMGB1的mRNA表达显著性上调,DMP1、DSPP和ALP的mRNA以及碱性磷酸酶活性在诱导7 d、11 d和14 d后与对照组间差异有统计学意义(P<0.05),HMGB1mRNA在矿化诱导11d和14d后与对照组的差异具有统计学意义(P<0.05)。蛋白印迹法检测示细胞内各矿化标记的蛋白表达均较对照组上调,而细胞内HMGB1的蛋白表达较对照组下调。免疫荧光结果显示hDPCs矿化过程中,HMGB1逐渐从胞核转移至胞浆。结论:在hDPCs诱导成牙本质细胞分化过程中,HMGB1在mRNA水平上与DMP1、DSPP和ALP的表达变化趋势相似,而细胞内HMGB1蛋白水平表达下调,且HMGB1在hDPCs细胞内出现转位,提示HMGB1与hDPCs的成牙本质分化有关,可能在牙髓细胞损伤修复中发挥作用。     

DSP、DMP1、CBFA1、BMP2在大鼠牙髓干细胞中的表达

目的检测DSP、DMP1、CBFA1、BMP2在大鼠牙髓干细胞中的表达,为大鼠牙髓干细胞的生物学功能研究提供基础。方法采用免疫组织化学染色的方法,对DSP、DMP1、CBFA1、BMP2在大鼠牙髓干细胞中的表达进行检测,然后采用矿化液对大鼠牙髓干细胞进行诱导,并对诱导后细胞进行DSP、DMP1表达的检测。结果大鼠牙髓干细胞DMP1仅个别细胞阳性表达,DSP少量细胞阳性表达,CBFA1、BMP2为阳性染色。经矿化液诱导后,大鼠牙髓干细胞DSP染色出现部分细胞强阳性,DMP1出现阳性结果。结论CBFA1、BMP2阳性表达表明大鼠牙髓干细胞具有一定的未成熟性,而经过诱导后出现牙本质特异性DSP的表达,表明大鼠牙髓干细胞可以被诱导向成牙本质细胞方向分化。     

大鼠牙本质基质蛋白1单克隆抗体的制备、鉴定及其在牙胚发育过程中的表达

目的：制备抗大鼠牙本质基质蛋白1（dentin matrix protein1,DMP1)的单克隆抗体，研究其在牙胚发育过程中的时空表达。方法：以重组的DMP1为抗原，免疫Balb/c小鼠，通过细胞融合，建立分泌单克隆抗体的杂交瘤细胞系，用免疫组化方法检测DMP1在牙胚发育过程中的表达。结果：获得了2株稳定分泌抗DMP1特异性抗体的杂交瘤细胞，两株单克隆抗体的亚类均为IgG1，与重组的DMP1蛋白和牙齿组织总蛋白均可特异性反应，DMP1在磨牙和切牙分泌性成牙本质细胞胞浆顶端及切牙成釉细胞中有表达，结论：通过杂交瘤技术，获得了2株抗DMP1的单克隆抗体，DMP1在大鼠磨牙发育过程中的分布具有时空特异性，可能促进牙本质矿化诱导前成釉细胞向成釉细胞分化。     

大鼠牙齿发育过程中骨涎蛋白和骨桥蛋白的表达

目的：探讨骨涎蛋白（bone sialoprotein BSP)和骨折蛋白（osteopontin,OPN)在大鼠牙齿发育中的时间和空间分布特点，及两者在矿化中的作用。方法：用免疫组化方法检测了SD大鼠出生后1d及1，2，3 ，5，8周的牙胚和颌骨中BSP及OPN的表达特点。结果：成熟的成釉细胞，成牙本质细胞，成牙骨质细胞和成骨细胞及基质中均表达BSP和OPN，牙骨质和牙槽骨中SBP和OPN的表达高于牙釉质的牙本质，在牙骨质和牙槽骨中，BSP在未矿化的基质和已矿化的基质中均有高表达，而OPN仅在矿化的前沿和新生线处有高表达。结论：BSP和OPN在大鼠牙齿及颌骨的形成和矿化中具有重要作用。尤其是OPN与牙釉质的形成也有重要关系。BSP和OPN的表达特点不同，提示二者在矿化组织的形成和矿化中的作用不同。     

牙本质基质蛋白-1与生物矿化

牙本质基质蛋白(DMP)-1是骨、软骨、釉质、牙骨质和牙本质生物矿化所必需的一种酸性非胶原蛋白.蛋白质化学研究显示,DMP-1全基因序列是生物矿化的启动因子,由C末端和N末端组成.体内实验证实DMP-1具有多方面功能,不仅是生物矿化的信号分子,同时也是调节因子,对成骨细胞和成牙本质细胞的成熟至关重要.本文就DMP-1在基因调节、组织细胞中的表达以及成骨、成牙本质中的生物矿化作用作一.     

骨折愈合中牙本质基质蛋白1与破骨细胞表达时间效应的观察

目的探讨骨折愈合过程中牙本质基质蛋白1（dentin matrix protein 1，DMP1）与破骨细胞的时间效应。为研究DMP1在体内矿化重建中的作用提供参考。方法将40只成年Wistar雄性大鼠左侧下颌支骨折，建立下颌骨骨折模型。骨折后5、7、14、21d处死大鼠，取骨痂和对侧正常骨组织（对照组），分别采用HE染色、TRAP染色和免疫组织化学链霉抗生物素．蛋白过氧化物酶（streptavidin perosidase，sp）法染色切片检测。结果在对照组正常下颌支组织中没有DMP1的表达，偶见破骨细胞；实验组在骨折后14～21d是破骨细胞活动高峰。结论DMP1与破骨细胞在骨折愈合过程中具有一定的时间效应。     

The influence of cigarette smoke inhalation and its cessation on the tooth-supporting alveolar bone: a histometric study in rats

OBJECTIVE: It has been previously shown that smoking may enhance periodontal breakdown and impair bone healing around titanium implants. However, there is a lack of information concerning the effect of smoking on the tooth-supporting alveolar bone. Thus, the aim of this study was to histometrically evaluate the influence of cigarette smoke inhalation and its cessation on tooth-supporting alveolar bone. METHODS: Sixty male Wistar rats were randomly assigned to one of the following groups: group 1 - control (n = 15), group 2 - 2 months of cigarette smoke inhalation (n = 13), group 3 - 3 months of cigarette smoke inhalation and 2 months without exposure to cigarette smoke inhalation (n = 16) and group 4 - 5 months of cigarette smoke inhalation (n = 16). Five months after the beginning of cigarette smoke inhalation regime (2 months for group 2), the animals were killed and the mandible was removed and prepared for histological sections. The proportion of mineralized tissue in the furcation area (i.e. a 1000 microm zone under the furcation and between the roots) was obtained. RESULTS: Data analysis demonstrated that the animals continuously exposed to cigarette smoke inhalation presented a decreased proportion of mineralized tissue (groups 2 and 4), when compared to control and cessation groups (groups 1 and 3) (p < 0.05). Similar levels of proportion of mineralized tissue were observed in groups 1 and 3, showing a beneficial effect of cigarette smoke inhalation cessation on proportion of mineralized tissue. CONCLUSION: Within the limits of the present study, it can be concluded that cigarette smoke inhalation may affect the tooth-supporting bone as early as 2 months after the initial exposure, and that smoke exposure cessation may revert its negative impact on the alveolar bone.     

Oral administration of vitamin C prevents alveolar bone resorption induced by high dietary cholesterol in rats

BACKGROUND: A high-cholesterol diet stimulates alveolar bone resorption, which may be induced via tissue oxidative damage. Vitamin C reduces tissue oxidative damage by neutralizing free radicals and scavenging hydroxyl radicals, and its antioxidant effect may offer the clinical benefit of preventing alveolar bone resorption in cases of hyperlipidemia. We examined whether vitamin C could suppress alveolar bone resorption in rats fed a high-cholesterol diet. METHODS: In this 12-week study, rats were divided into four groups: a control group (fed a regular diet) and three experimental groups (fed a high-cholesterol diet supplemented with 0, 1, or 2 g/l vitamin C). Vitamin C was provided by adding it to the drinking water. The bone mineral density of the alveolar bone was analyzed by microcomputerized tomography. As an index of tissue oxidative damage, the 8-hydroxydeoxyguanosine level in the periodontal tissue was determined using a competitive enzyme-linked immunosorbent assay. RESULTS: Hyperlipidemia, induced by a high-cholesterol diet, decreased rat alveolar bone density and increased the number of tartrate-resistant acid phosphatase-positive osteoclasts. The expression of 8-hydroxydeoxyguanosine was upregulated in the periodontal tissues. Intake of vitamin C reduced the effect of a high-cholesterol diet on alveolar bone density and osteoclast differentiation and decreased periodontal 8-hydroxydeoxyguanosine expression. CONCLUSION: In the rat model, vitamin C suppressed alveolar bone resorption, induced by high dietary cholesterol, by decreasing the oxidative damage of periodontal tissue.     

Periodontal breakdown in the Dmp1 null mouse model of hypophosphatemic rickets

Dentin Matrix Protein 1 (DMP1) is highly expressed in alveolar bone and cementum, which are important components of the periodontium. Therefore, we hypothesized that Dmp1 is critical for the integrity of the periodontium, and that deletion may lead to increased susceptibility to disease. An early-onset periodontal defect was observed in the Dmp1 null mouse, a mouse model of hypophosphatemic rickets. The alveolar bone is porous, with increased proteoglycan expression. The cementum is also defective, as characterized by irregular, punctate fluorochrome labeling and elevated proteoglycan. The osteocyte and cementocyte lacuno-canalicular system of both alveolar bone and cementum is abnormal, with irregular lacunar walls and fewer canaliculi. As a consequence, there is significant interproximal alveolar bone loss, combined with detachment between the periodontal ligament (PDL) and cementum. We propose that defective alveolar bone and cementum may account for the periodontal breakdown and increased susceptibility to bacterial infection in Dmp1 null mice.     

两种异常咬合刺激对小鼠髁突影像及组织形态学影响研究

目的 探究异常咬合刺激对小鼠髁突影像及组织形态学影响.方法 选取6周龄雌性C57BL/6J小鼠36只,根据饲养时间(3、7周)均分小鼠后,再随机分为对照组、单侧前牙反(unilateral anterior crossbite,UAC)组和双侧前牙咬合抬高(bilateral anterior elevation,B...     

Effects of cyclosporin A on alveolar bone: an experimental study in the rat

BACKGROUND: There have been several investigations on the role of cyclosporin A (CSA) in gingival hyperplasia in both animals and humans. However, less attention has been given to the drug's effect on alveolar bone. This study used light microscopy to histologically and histometrically evaluate the effects of CSA on alveolar bone in the rat. METHODS: Sixty, 6-week-old Sprague-Dawley rats were separated into test and control groups. Animals in the test group received CSA in mineral oil (30 mg/kg body weight) daily by gastric feeding over the 6-week study. Control animals received only mineral oil. Ten animals from each group were sacrificed at weeks 2, 4, and 6. After histologic processing, the labial crest of the alveolar bone in the anterior mandible was evaluated by light microscopy. RESULTS: A distinct pattern of increased osteoclasia and reduced bone formation was observed in the CSA-exposed animals compared to the controls. Increased osteoclasia was observed in periodontal sites and decreased bone formation was observed in symphyseal sites. CONCLUSIONS: The results suggest that CSA has distinct effects on alveolar bone.     

sclerostin在2型糖尿病伴牙周炎大鼠牙槽骨骨重建过程中的表达及意义

目的： 观察2型糖尿病（T2DM）伴牙周炎大鼠牙槽骨骨重建过程中骨硬化蛋白（sclerostin）的表达。方法： 将54只SD大鼠随机分为健康组、牙周炎组、T2DM伴牙周炎组,每组各18只。牙周炎组建立牙周炎大鼠模型,T2DM伴牙周炎组先建立T2DM模型,再建立牙周炎模型。腹腔注射STZ后1、5、10 d,检测糖代谢指标。结扎后8周,检测牙周指标。建模成功后1、3、6个月,免疫组织化学染色检测牙槽骨组织中sclerostin的表达。采用SPSS 21.0软件包对数据进行统计学分析。结果： 与未建模大鼠相比,T2DM建模大鼠腹腔注射STZ后1、5、10 d空腹血糖（FBG）,腹腔注射STZ后10 d空腹胰岛素（FINS）及胰岛素抵抗指数（HOMA-IR）均显著升高（P<0.05）。与未建模大鼠相比,牙周炎建模大鼠牙龈出血指数（SBI）、菌斑指数（PLI）、探针深度（PD）均显著增加（P<0.05）。与健康组相比,牙周炎组、T2DM伴牙周炎组建模成功后1、3、6个月牙槽骨组织中sclerostin表达显著增加（P<0.05）,且T2DM伴牙周炎组显著高于牙周炎组（P<0.05）。与建模成功后1个月相比,牙周炎组、T2DM伴牙周炎组建模成功后3、6个月牙槽骨组织中sclerostin表达显著增加（P<0.05）。与建模成功后3个月相比,牙周炎组、T2DM伴牙周炎组建模成功后6个月牙槽骨组织中sclerostin表达显著减少（P<0.05）。结论： sclerostin在牙周炎中表达增加,且合并T2DM进一步上调sclerostin的表达,但在骨重建过程中逐渐下调。     

咬合力丧失对大鼠牙周组织中iNOS表达的影响

目的：研究在体内咬合力丧失的情况下,iNOS影响牙周组织改建的分子机制。方法：选用Wistar大鼠,建立咬合力丧失的动物模型,按照正常及拔牙后6h、1d、2d．3d、1周、2周、3周、4周随机分组,采用HE、免疫组化染色和RT—PCR方法,对实验结果进行单向方差分析、Dunnett检验和配对t检验．分析牙周形态变化以及牙周组织中iNOS蛋白表达的动态变化。结果：组织形态学观察发现,实验组的牙周组织较对照组有明显改建：牙周膜结构由致密变得稀疏,纤维、细胞的排列由有序到紊乱,牙槽骨骨壁由平整变得凹凸不平,甚至出现破骨细胞等。免疫组化染色结果显示：iNOS在对照组牙周膜的成纤维细胞和成骨细胞中仅表现为少量的棕黄色颗粒,而在实验组中的表达则明显增强,尤其是拔牙后的第2天和第3周。RT—PCR结果显示：咬合力丧失后,iNOSmRNA的表达呈现一定的规律性．并在拔牙后第2天、第3周先后出现2次表达高峰。统计学分析显示：实验组中iNOSmRNA的表达与咬合力的丧失有关（P〈0．01）,其中拔牙后的第2天和第3周与对照组的差异最为显著。结论：咬合力丧失促使牙周组织产生iNOS明显增多,且呈一定的规律性变化,导致牙周组织发生一系列退行性改变,提示iNOS很有可能是影响牙周组织改建的一个重要因素．