甲状旁腺激素对去卵巢大鼠骨质疏松牙周炎模型骨代谢的影响

目的：观察甲状旁腺激素对去卵巢大鼠骨质疏松牙周炎模型骨代谢的影响。方法：4月龄健康雌性Wistar大鼠68只,随机分成4组,每组17只。即A组（健康对照组）、B组（伪手术组）、C组（去势牙周炎组）,D组（去势牙周炎加甲状旁腺激素治疗组）。模型建立成功后,A、B、C组腹腔内注射等量的生理盐水,D组间歇性小剂量腹腔内注射等量甲状旁腺激素,隔日注射一次,用药8周。治疗后处死大鼠并通过CBCT扫描测定上颌骨密度,检测血清中钙（Ca2＋）、磷（P3＋）、碱性磷酸酶（ALP）水平。结果：治疗8周后,经CBCT图像测量,D组上颌骨密度较C组明显升高,差异有统计学意义（P〈O．05）,与A、B组上颌骨密度无明显差异,无统计学意义（P〉0．05）。D组外周血中ALP水平高于A、B、C组（P〈0．05）,差异有统计学意义,各组血清钙、磷值没有明显改变（P〉0．05）。结论．小剂量注射甲状旁腺激素能够增加骨密度并改善外周血中ALP的水平,促进牙槽骨的形成,对绝经期后牙周炎有明显的治疗作用。     

骨髓间充质干细胞对关节盘细胞的作用研究

目的探讨大鼠骨髓间充质干细胞（BMSC）对颞下颌关节盘软骨细胞的作用。方法大鼠骨髓来源的间充质干细胞三向分化鉴定其干性,大鼠关节盘软骨细胞Ⅱ型胶原免疫荧光染色,收取BMSC培养24h上清液制作条件培养基。CCK-8检测条件培养基对关节盘软骨细胞细胞增殖影响,反转录聚合酶链反应（RT-PCR）分析条件培养基培养7、14d关节盘软骨Ⅰ、Ⅱ、X型胶原基因表达。两组比较采用独立样本t检验,进行统计学分析。结果获取的大鼠BMSC具备三向分化能力．大鼠关节盘软骨细胞Ⅱ型胶原免疫荧光表达。CCK-8结果显示,培养48h后条件培养基组细胞增殖速度明显加快,差异具有统计学意义（t=10．75,P〈0．05）;RT-PCR结果显示：条件培养基组7d时抑制X型胶原表达（t=2．586,P〈0．05）,14d时促进Ⅱ型胶原表达（t=6．501,P〈0．05）。结论大鼠BMSC分泌物促进关节盘软骨细胞增殖,抑制关节盘软骨细胞肥大发挥保护作用。     

甲状旁腺激素与雌激素对去势雌性大鼠牙槽骨代谢的影响

目的 观察甲状旁腺激素与雌激素单独和联合应用对去势雌性大鼠牙槽骨代谢的影响。方法选用4月龄雌性Wistar大鼠66只,分成两组,分别为伪手术组（n=18）和去势组（n=48）。8周后各处死8只证实骨质疏松造模成功。剩余的伪手术组（A组,n=10）Wistar大鼠作为对照;将剩余的去势组Wistar大鼠随机分成4组,分别为去势组（B组）、去势加雌激素组（C组）、去势加甲状旁腺激素组（D组）、去势加雌激素和甲状旁腺激素组（E组）,每组10只。A组和B组注射生理盐水（1 mL·kg-1）;C组注射苯甲酸雌二醇（10 μg·kg-1）; D组注射甲状旁腺激素（20 μg·kg-1）;E组注射苯甲酸雌二醇（10 μg·kg-1）和甲状旁腺激素（20 μg·kg-1）。隔日腹腔注射1次,用药8周。治疗后处死大鼠并测定牙槽骨骨密度,观察每组大鼠骨组织形态计量学参数及血清钙、磷、碱性磷酸酶（ALP）水平。结果去势手术8周后,去势组大鼠牙槽骨密度明显低于伪手术组（P<0.05）。用药8周后,C、D、E组骨密度、骨小梁面积百分比（%Tb.Ar）、骨小梁宽度（Tb.Th）和骨小梁数量（Tb.N）较B组均有明显提高,其中E组提高最明显（P<0.05）。各组血清钙磷值无明显改变（P>0.05）,B组ALP值较A组明显升高（P<0.05）。结论间歇性、小剂量注射甲状旁腺激素能增加去势大鼠牙槽骨的骨密度和改善骨结构,与雌激素联合使用对骨质疏松的治疗有协同作用。     

橙皮苷防龋作用的动物实验研究

目的：研究橙皮苷在大鼠体内的防龋作用。方法：纸片扩散法检测橙皮苷对远缘链球菌（S．sobrinus）的最小抑菌浓度（MIC）,接种S．sobrinus建立大鼠龋病模型,分别用1／2 MIC橙皮苷、0．12％洗必泰、无菌蒸馏水处理大鼠口腔,菌落计数法动态监测S．sobrinus水平、Keyes龋齿评分法、激光龋齿诊断仪（DIAGNOdent）探测荧光值评价不同处理方法对大鼠龋病发生的影响。结果：橙皮苷的MIC为8 mg／ml;S．sobrinus水平：橙皮苷组与蒸馏水组相比差异无统计学意义（P＞0．05）;Keyes记分：橙皮苷组光滑面及窝沟E级龋损记分低于蒸馏水组（P＜0．05）,橙皮苷组窝沟Ds级、Dm级龋损记分低于蒸馏水组（P＜0．05）,高于洗必泰组（P＜0．05）;DIAGNOdent探测荧光值：橙皮苷组龋损程度低于蒸馏水组（P＜0．05）,高于洗必泰组（P＞0．05）。结论：1／2 MIC橙皮苷在不影响大鼠口内菌群水平的前提下,可减少大鼠磨牙龋病形成及减轻龋损程度。     

microRNA-145调控大鼠骨髓间充质干细胞成骨分化的实验研究

目的探讨microRNA-145在大鼠骨髓间充质干细胞成骨分化过程中的作用。方法取3周龄雄性大鼠胫骨骨髓间充质干细胞,分为阴性对照组与microRNA-145下调组,分别感染慢病毒,观察microRNA-145对大鼠骨髓间充质干细胞在细胞增殖、细胞周期、凋亡和成骨分化方面的影响。结果 microRNA-145下调表达组(p Lv3-(anti)miR-145)与阴性对照组(p Lv3-Negative control)相比,大鼠骨髓间充质干细胞的增殖、细胞周期和凋亡无统计学差异(P>0.05);microRNA-145下调表达组成骨相关基因Sema3A、OPG、Runx2及Osterix/SP7表达均明显高于阴性对照组,且microRNA-145下调组茜素红染色范围也大于阴性对照组。结论 microRNA-145下调表达可以促进大鼠骨髓间充质干细胞的成骨分化,但对其细胞增殖、细胞周期和凋亡无明显影响。     

雌激素对大鼠骨髓间充质干细胞增殖及成骨分化的影响

目的： 应用17 β-雌二醇（E₂）作用于大鼠骨髓间充质干细胞,研究不同浓度雌激素对细胞增殖、凋亡及成骨分化的影响。方法：原代培养大鼠骨髓间充质干细胞（rat bone mesenchymal stem cells,rBMSCs）,加入0、10^-9和10^-7 mol/L不同浓度E₂,CCK-8及Annexin V/PI双染法检测E₂对细胞增殖与凋亡的影响。分别于成骨诱导后第1、3、5、7、11、14和21天,采用碱性磷酸酶（alkaline phosphatase,ALP）活性测定、ALP和钙结节染色,以及实时定量PCR等方法检测不同浓度E₂对细胞成骨向分化能力的影响。采用SPSS19.0软件包对数据进行统计学分析。结果：E₂对大鼠骨髓间充质干细胞增殖与凋亡未见明显影响,并能显著提高干细胞的成骨分化能力,浓度为10^-9 mol/L时促进作用最为明显。与对照组相比,加药组细胞ALP活性升高,钙结节形成增多,成骨相关基因（RUNX2、ALP、COL I、OCN）表达显著升高。结论：17 β-雌二醇能促进大鼠骨髓间充质干细胞成骨分化,体外浓度为10^-9 mol/L时,作用最为显著。     

纳米珍珠粉对小鼠骨髓间充质干细胞活性影响研究

目的    探讨纳米珍珠粉（nano-pearl powder，NPP）对小鼠骨髓间充质干细胞活性的影响。方法    研究于2016年8月至2017年3月在中南大学湘雅医学院附属海口医院实验中心进行。 将NPP以100、300、500 μg/mL的质量浓度与小鼠骨髓间充质干细胞共培养24 h（NPP组），用CCK8法测定吸光度值，计算细胞相对增殖率，评定其细胞毒性级别；用Annexin-FITC/PI法检测细胞凋亡率。两者综合评定NPP对小鼠骨髓间充质干细胞活性的影响，并与相同质量浓度纳米羟基磷灰石（nano-hydroxyapatite，NHA）（NHA组）进行对比。结果    NPP与NHA细胞毒性检测均合格，NPP在100 μg/mL时细胞相对增殖率最高；NPP组细胞凋亡率均低于NHA组，在质量浓度为100和500 μg/mL时的差异有统计学意义（P < 0.01）。结论    NPP细胞毒性检测合格，其对小鼠骨髓间充质干细胞活性的影响优于NHA。     

苯妥英钠对大鼠骨髓间充质干细胞向血管内皮细胞分化的影响

目的：研究苯妥英钠（PHT）对大鼠骨髓间充质干细胞（rBMSCs）向血管内皮细胞（rVECs）分化的影响。方法：建立rBMSCs 与 rVECs 共培养组及 rBMSCs 单独培养组,各组分别添加不同浓度的 PHT（0、20、40μg／ml）,培养14 d 后 real-time PCR 检测各组细胞中 ICAM-1、VCAM-1、KDR 和 RUNX2基因的 mRNA 表达水平。结果：添加 PHT 后,各组细胞中 ICAM-1、KDR 和 RUNX2基因的 mRNA 表达均上调。添加相同浓度 PHT 时,共培养组较单独培养组中 rBMSCs 的 ICAM-1、KDR 和RUNX2基因的 mRNA 表达量增高,而 VCAM-1基因的 mRNA 表达量降低。结论：PHT 可能促进大鼠骨髓间充质干细胞向血管内皮细胞分化。     

瘦素在种植体骨结合中的作用研究

摘要：目的：体外实验研究瘦素对大鼠骨髓间充质干细胞在纯钛表面增殖、分化的影响。 方法：将体外培养的SD大鼠骨髓间充质干细胞接种于钛片表面,实验组加入50nmol/L瘦素,比较实验组与对照组ALP、OC的含量,以及MTT法检测瘦素对细胞增殖的影响。 结果：实验组与对照组之间ALP、OC情况均有统计学差异（P<0.05）,对细胞增殖无明显促进作用。 结论：瘦素能够促进钛片表面骨髓间充质干细胞的分化。     

英文文摘

1．香豆素类衍生物蛇床子素对人牙周膜和颌骨骨髓间充质干细胞膜片成骨性能的影响（英）／Gao LN…／／Biomateri-als．-2013,34（38）．-9937-9951
　　细胞膜片工程是一种无支架的过渡性方法,可在临床前和临床试验中改善由间充质干细胞介导的外伤或病理性损伤牙周组织的再生。然而,细胞膜片生产的最佳策略还有待确定。本研究是探讨蛇床子素（一种香豆素类衍生物,从中药中提取得到）对人牙周膜干细胞（PDLSCs）及颌骨骨髓间充质干细胞（JBMMSCs）的细胞膜片形成和成骨性能的生物学影响。我们将匹配患者的 PDLSCs和 JBMMSCs进行分离,通过评价两种细胞类型的细胞增殖能力和碱性磷酸酶（ALP）活性,筛选出细胞培养中合适的蛇床子素浓度。接着,通过评价各类型细胞的胞外基质（ECM）蛋白的生成及成骨相关基因的表达量来选择蛇床子素诱导各类型细胞膜片形成的最佳刺激方式。此外,将优化后的 PDLSC 和JBMMSC 膜片移植于裸鼠皮下,以评估其异位骨再生的能力。结果表明：尽管4组中不同蛇床子素浓度对 JBMMSCs的增殖影响无差异（P＞0．05）,10-5 m／L 浓度的蛇床子素能显著提高 PDLSCs 和 JBMMSCs 的增殖能力（P＜0．05）,10-5 m／L浓度的蛇床子素是提高两种细胞 ALP 活性的最佳浓度。根据细胞外基质蛋白（I 型胶原酶、整合素β1和纤连蛋白）的生成及成骨基因（ALP,RUNX2和 OCN）的表达情况,在 PDLSCs整个培养阶段（10 d）或 JBMMSCs 培养早期（前3 d）,加入10-5 m／L浓度蛇床子素进行刺激,是蛇床子素作用于细胞膜片形成的最有效给药方式（P ＜0．05）。体内移植结果表明蛇床子素介导的 PDLSC 和JBMMSC 膜片,较无蛇床子素干预组形成更多新骨（P＜0．001）。此研究表明适当浓度和给药方式的蛇床子素刺激可增强 ECM生成,并显著影响细胞膜片工程中的细胞行为。     

The mechanically activated p38/MMP-2 signaling pathway promotes bone marrow mesenchymal stem cell migration in rats

ObjectiveThe aim of the present study was to investigate the effect of static strain on bone marrow mesenchymal stem cell (BMMSC) migration and whether the p38/matrix metalloproteinase-2 (MMP-2) axis plays a role in induction of BMMSC migration under mechanical strain.DesignBoth in vivo and in vitro investigations were performed. Twelve adult male Sprague-Dawley rats were randomly divided into 2 groups (n = 6 per group). Rats in the experimental group underwent right mandibular distraction osteogenesis, whereas rats in the control group were subjected to osteotomy in the mandible without distraction. Immunohistochemistry and immunofluorescence were performed to evaluate phospho-p38 (p-p38) and Nestin expression. BMMSCs were isolated from rat mandibles. BMMSCs in the experimental group were subjected to static mechanical strain for 2 h, whereas those in the control group underwent no strain. The biological roles of static strain and the p38/MMP-2 axis in BMMSC migration were evaluated by Transwell assays and western blotting by inhibiting p38 phosphorylation.ResultsThere were significantly more Nestin⁺ cells in the bone calluses of the experimental group than in those of the control group. In addition, Nestin⁺/p-p38⁺ cell numbers were significantly higher in the experimental group than in the control group, indicating that static strain activated p38 signaling in BMMSCs in vivo. In accordance with in vivo results, static strain in vitro stimulated phosphorylation of p38 in BMMSCs. Furthermore, expression of MMP-2 was elevated in BMMSCs under static strain compared with the control, and strain-induced MMP-2 expression was abolished by inhibition of p38 phosphorylation in BMMSCs. Moreover, Transwell assay results showed that static strain promoted BMMSC migration, which was abolished by inhibition of p38 phosphorylation.ConclusionsThe present study demonstrated that static strain can promote the migration ability of BMMSCs via p38/MMP-2 signaling. To the best of our knowledge, this study is the first report demonstrating that the p38/MMP-2 axis governs BMMSC migration under static mechanical strain.     

Mouse mandible contains distinctive mesenchymal stem cells

Although human orofacial bone-marrow-derived mesenchymal stem cells showed differentiation traits distinctly different from those of mesenchymal stem cells (MSCs) derived from long bone marrow (BMMSCs), mouse MSCs derived from orofacial bone have not been isolated due to technical difficulties, which in turn precludes the use of mouse models to study and cure orofacial diseases. In this study, we developed techniques to isolate and expand mouse orofacial bone/bone-marrow-derived MSCs (OMSCs) from mandibles and verified their MSC characteristics by single-colony formation, multi-lineage differentiation, and in vivo tissue regeneration. Activated T-lymphocytes impaired OMSCs via the Fas/Fas ligand pathway, as occurs in BMMSCs. Furthermore, we found that OMSCs are distinct from BMMSCs with respect to regulating T-lymphocyte survival and proliferation. Analysis of our data suggests that OMSCs are a unique population of MSCs and play an important role in systemic immunity. Abbreviations: BMMSC, bone marrow mesenchymal stem cell; HA/TCP, hydroxyapatite/tricalcium phosphate; OMSC, orofacial mesenchymal stem cell; OVX, ovariectomized.     

大鼠骨髓间充质干细胞膜片的构建及其特性

目的:探讨大鼠骨髓间充质干细胞膜片的构建和基本生物学特性。方法:从GFP-SD荧光大鼠体内提取原代骨髓并培养骨髓间充质干细胞(BMMSCs),鉴定后用于体外构建BMMSCs细胞膜片,用荧光显微镜、倒置显微镜和HE染色对膜片进行形态学检测,并提取膜片RNA用于RT-PCR实验,检测相关促愈合因子的表达情况。结果:BMMSCs成功分离、培养和鉴定。体外诱导培养2周后获得白色膜状细胞膜片,并可用机械力刮下。显微观察显示细胞呈长梭形重叠生长,染色显示细胞间紧密连接并分泌大量细胞外基质(ECM)。RT-PCR结果显示,膜片细胞与正常培养的BMMSCs相比,高表达TGF-β、FGF、VEGF和ColⅠ等细胞因子和蛋白,但在诱导1周和2周时的表达量无显著差异。结论:本方法能够较为稳定的在体外构建BMMSCs膜片,该膜片显著高表达TGF-β等促愈合因子。     

大豆苷元对骨质疏松模型大鼠拔牙后牙槽窝骨修复的影响

目的:研究大豆苷元(Daidzein, Da)对骨质疏松模型大鼠拔牙后牙槽窝处骨修复的影响。方法:24只3月龄大鼠随机均分为4组:假手术组(Sham)、雌激素组(EG)、大豆苷元组(Da)(75 mg/kg·d^-1)和去卵巢组(Ovx)。摘除卵巢1周后,所有大鼠拔去双侧上颌第一磨牙,第12周检测血清钙、磷含量及总碱性磷酸酶(alkaline phosphatase, ALP)活性,制作左侧上颌骨拔牙窝处骨组织切片,于光镜下观察牙槽窝骨修复情况。结果:去卵巢后大鼠血清钙含量(2.10±0.04)及ALP活性(3.47±0.36)显著性降低(P<0.01),大豆苷元能显著提高去卵巢后大鼠血清钙含量(2.27±0.05)及ALP活性(4.49±0.38)(P<0.01)。骨形态观察表明大豆苷元对于牙槽窝的骨保存功能与雌激素相似,与Sham组骨形态结构较接近。结论:大豆苷元能有效改善骨质疏松模型大鼠拔牙后血清钙含量和ALP水平,减少牙槽窝骨吸收并恢复骨形态。     

骨形态发生蛋白6对张应力下大鼠骨髓间充质干细胞成骨分化的影响

目的:探讨骨形态发生蛋白-6(BMP-6)对张应力作用下大鼠骨髓间充质干细胞(BMMSCs)成骨向分化的影响。方法:应用四点弯曲加力系统对体外分离培养大鼠BMMSCs施加不同大小的周期单一张应力60 min,2 h后检测检测内源性BMP-6的表达量,同时检测碱性磷酸酶、骨钙素表达量和进行成骨细胞转录因子-2mRNA定量分析。然后对体外分离培养转染人BMP-6复制缺陷型病毒的大鼠BMMSCs施加4000μstrain的周期单一张应力60 min,2 h后检测成骨标志表达。结果:随着张应力的增大,BMP-6的表达逐渐增强,同时成骨能力亦增强,但2000 μstrain以后BMP-6的表达与成骨能力均下降。4000 μstrain条件下2 h后转染人BMP-6基因的大鼠BMMSCs各项成骨标志因子的检测明显强于转染空白病毒。结论:适当的张应力可促进BMP-6表达上调和BMMSCs骨向分化,上调BMP-6的表达可以恢复过大张应力所致的成骨能力下降。     

利塞膦酸钠对骨质疏松大鼠牙槽骨Bcl-2、BAX表达的影响

目的: 观察利塞膦酸钠对骨质疏松大鼠下颌牙槽骨显微结构、抗凋亡因子Bcl-2、凋亡因子BAX表达以及骨细胞凋亡的影响。方法: 30只6月龄雌性SD大鼠,随机分为3 组（每组10只）,即Sham组（假手术组）、OVX组（接受双侧卵巢切除术）和RIS组（接受双侧卵巢切除术,然后给予利塞膦酸钠）;造模3个月后,取各组大鼠下颌骨进行micro-CT扫描,并通过TUNEL染色以及Bcl-2、BAX免疫组织化学染色检测下颌骨骨细胞的凋亡。采用SPSS 13.0软件包对组间数据进行比较。结果: 与Sham组相比,OVX组牙槽骨丧失和骨细胞凋亡明显增多;RIS组与OVX组相比,骨细胞凋亡显著减少,BV/TV显著增加,Bcl-2 表达增加,Bcl-2/BAX比值增加（P<0.05）。结论: 利塞磷酸钠增加下颌牙槽骨中Bcl-2的表达和Bcl-2/BAX的比值,部分逆转去卵巢骨质疏松大鼠的牙槽骨丧失,减少下颌骨骨细胞凋亡。     

Effect of intermittent PTH administration in the periodontitis-associated bone loss in ovariectomized rats

OBJECTIVE: Parathyroid hormone intermittent administration has been considered to treat bone mass decrease in osteoporotic individuals. The present study evaluates whether PTH can affect alveolar bone loss in ovariectomized rats, since estrogen deficiency has been proposed as a risk factor for periodontal disease. DESIGN AND METHODS: Thirty female rats were set in groups: ovariectomized (Ovx) and Sham operated. Ovx were divided in two groups: Ovx-PTH (1-34) treated and Ovx, which received vehicle. After 1 week, cotton ligature was placed around one lower first molar of all animals to induce periodontal disease. Ovx treated received PTH doses of 40 microg/kg, three times a week for 30 days. After that, the animals were sacrificed, the mandibles extracted, X-rayed and samples prepared for histological evaluation. Histomorphometry was performed using image analyzer software. Scanning electron microscopy (SEM) of the tibias was also performed in all animals to evaluate possible changes in bone structure caused by the estrogen deficiency. Optical densities of the radiographs were measured by aluminum step-wedge equivalent thickness. RESULTS: Histomorphomery indicated the anabolic PTH effect in ovariectomized rats with significant inhibition of periodontitis manifestation (p<0.05) thus neutralizing the periodontitis inductor effects. The photo densitometry showed a lower mandibular optical density in the ovariectomized group that did not receive PTH (p<0.05). SEM image confirmed the early effect of estrogen deficiency in osseous tissue and PTH anabolic effect. CONCLUSION: PTH systemic intermittent administration was able to reduce alveolar bone loss in ovariectomized rats, despite the presence of a periodontal disease inductor and estrogen deficiency.     

Rho激酶抑制剂Y-27632对人牙髓干细胞增殖能力的影响

目的: 初步研究Rho激酶抑制剂Y-27632对人牙髓干细胞(human dental pulp stem cells,hDPSCs)增殖能力的影响。方法: 采用体外贴壁式培养法培养人牙髓干细胞,应用Rho激酶抑制剂Y-27632,根据培养条件,分为普通培养液培养组(Con)及普通培养液+抑制剂Y-27632培养组(Con+Y),采用MTT法检测两种培养条件下人牙髓干细胞培养24、48、72、96 h细胞活性;采用DAPI染色法及流式细胞定量检测技术(FCM)比较两组在培养48 h的细胞数量及细胞周期分布情况。结果: MTT结果显示,实验组hDPSCs细胞增殖曲线较对照组明显上移,且增殖高峰期提前;培养48 h,DAPI染色结果显示,实验组细胞总数量明显多于对照组;FCM结果显示,对照组G₀/G₁期细胞比例为(66.8±6.84)%,S期细胞比例为(25.17±0.62)%,实验组G0/G1期细胞比例为(58.59±1.76)%,S期细胞比例为(31.34±1.16)%,实验组S期细胞比例明显高于对照组(P<0.05)。 结论: Rho激酶抑制剂Y-27632促进人牙髓干细胞DNA合成、细胞分裂及增殖。     

神经钙黏素表达下调对舌鳞状细胞癌细胞生物学能力的影响

目的 研究神经钙黏素(N-cadherin)表达下调对舌鳞状细胞癌Tca8113细胞增殖、细胞周期、凋亡以及迁移的影响,并探讨其可能的分子机制.方法 利用LipofectamineTM2000将神经钙黏素siRNA转染舌鳞状细胞癌Tca8113细胞,将细胞分为3组:①未处理组;②对照siRNA组;③神经钙黏素siRNA组.分别收集转染后48 h的细胞,采用新型的细胞计数试剂盒(cell counting kit,CCK)8试剂分析转染神经钙黏素siRNA后对细胞增殖能力的影响;运用流式细胞术检测下调神经钙黏素表达对Tca8113细胞周期及细胞凋亡的影响;采用Boyden 小室实验分析下调神经钙黏素对舌鳞状细胞癌细胞Tca8113细胞迁移能力的影响;进一步采用蛋白质印迹法检测神经钙黏素表达下调对细胞增殖、细胞周期以及细胞迁移相关基因表达的影响.结果 神经钙黏素siRNA能明显下调舌鳞状细胞癌Tca8113细胞中神经钙黏素蛋白的表达,并显著抑制Tca8113细胞的增殖(P<0.05).细胞周期结果显示,神经钙黏素siRNA组中在G0/G1的细胞比率[(65.41±0.92)%]明显高于未处理组[(41.59±1.43)%]和对照siRNA组[(43.70±2.08)%],差异有统计学意义(F=216.839,P＝0.000).神经钙黏素siRNA组中细胞凋亡的比率[(25.66±1.36)%]明显高于未处理组[(2.38±0.14)%]和对照siRNA组[(2.81±0.12)%],差异有统计学意义(F=850.364,P=0.000).Boyden 小室体外侵袭实验结果表明,与未处理组和对照siRNA组相比,神经钙黏素siRNA组中Tca8113细胞的迁移能力显著下降,差异有统计学意义(F=140.858,P=0.000).蛋白质印迹法结果表明,与未处理组和对照siRNA组相比,神经钙黏素siRNA组中的基质金属蛋白酶(matrix metalloproteinases,MMP)2和MMP-9明显下调,而p21明显上调,且差异有统计学意义(P<0.05).结论 神经钙黏素在舌鳞状细胞癌的发生发展中可能具有重要的作用.

Abstract：

Objective To investigate the effect of downregulation of N-cadherin expression on cell proliferation, cell cycle, cell apoptosis and cell migration in tongue squamous cell carcinoma cell line Tca8113 cells. Methods N-cadherin siRNA was transfected into tongue squamous cell carcinoma cell line Tca8113 cells and Tca8113 cells were divided into three groups: untreated group, control siRNA group and N-cadherin siRNA group. The cells were harvested 48 h after transfection with N-cadherin siRNA. Cell proliferation of Tca8113 cells was examined by cell counting kit(CCK)-8 after transfection with N-cadherin, and the effects of downregulation of N-cadherin on cell cycle and cell apoptosis of Tca8113 cells were investigated by flow cytometry.The effect of downregulation of N-cadherin expression on cell migration of Tca8113 cells was observed by Boyden chamber experiment, and further expression changes of gene-related cell proliferation, cell cycle and cell migration were detected by Western blotting. Results N-cadherin siRNA downregulated the N-cadherin expression and significantly inhibited cell proliferation of Tca8113 cells (P<0.05). The results of cell cycle revealed that the percentage of G0/G1 phase in N-cadherin group [(65.41±0.92) %] was significantly higher than that in untreated group [(41.59±1.43)%] or control siRNA group [(43.70±2.08)%], and there was significant difference among the three groups (F=216.839,P＝0.000).The percentage of cell apoptosis in N-cadherin group [(25.66±1.36)%] was significantly higher than that in untreated group [(2.38±0.14)%] or control siRNA group [(2.81±0.12)%], and there was significant difference among the three groups (F=850.364,P=0.000). The cell number migrated into memebrane in N-cadherin group was significantly lower than that in untreated group and control siRNA group, and there was significant difference among the three groups (F=140.858,P=0.000). Further, compared with untreated group and control siRNA group, the expressions of matrix metalloproteinase(MMP)-2 and MMP-9 proteins were significantly downregulated and expression of p21 protein was significantly upregulated (P<0.05). Conclusions N-cadherin may play a role in occurrence and development of tongue squamous cell carcinoma.     

Effect of intermittent parathyroid hormone (1-34) treatment on the bone response after placement of titanium implants into the tibia of ovariectomized rats.

PURPOSE: This study investigated the effect of parathyroid hormone (1-34) [PTH(1-34)] on bone reactions after tibial placement of titanium screw implants into ovariectomized rats. MATERIALS AND METHODS: Twelve-week-old female Wistar rats were divided into 3 groups of 24. The first group (Sham group) was sham-operated; the second group (OVX group) was ovariectomized only; and the third group (PTH group) was subcutaneously administered 30 microg/kg PTH in the dorsal region 3 days per week starting the fourth week after ovariectomy until the end of the experiment. Titanium screw implants were placed in the proximal metaphysis of the tibia of all 3 groups at 168 days after surgery. The animals were killed 7, 14, 28, and 56 days after implantation. Undecalcified sections were prepared and evaluated by light microscopy. Histomorphometric measurements were obtained using a computer-based image analyzer to quantify the unit bone mass around the implant and the rate of implant-bone contact. RESULTS: When PTH administration was started 21 days after ovariectomy, the volume density of bone around implants in the PTH group was almost the same as that of the Sham group throughout the entire observation period. This finding suggests that not only can intermittent human PTH(1-34) administration prevent resorption of newly generated trabeculae around an implant but also it can aid in the recovery of bone volume lost due to ovariectomy. CONCLUSION: When dental implants are applied to jaw bone showing trabecular bone loss, it may be possible to increase bone density around an implant by intermittent human PTH(1-34) administration and thereby improve clinical results.