辛伐他汀对人牙周膜细胞增殖和分化的影响

目的:研究辛伐他汀对人牙周膜细胞增殖和成骨分化的影响.方法:将第4 代人牙周膜细胞在条件矿化培养液中诱导培养,同时加入不同浓度的辛伐他汀(10-9、10-8、10-7、10-6 mol/L),噻唑蓝(methyl thiazolyl tetrazolium,MTT)法检测细胞增殖情况,4-硝基苯基磷酸二钠盐(4-nitrophenyl phosphate,hexahydrate,PNPP)偶氮法检测碱性磷酸酶(alkaline phosphatase,ALP)活性.结果:辛伐他汀各浓度组均能促进人牙周膜细胞的增殖和分化,其中10-8、10-7、10-6 mol/L组与对照组比较,差异有统计学意义(P<0.05),10-7 mol/L的辛伐他汀组促进细胞增殖和ALP活性的作用最明显.结论:适宜浓度的辛伐他汀可有效促进人牙周膜细胞的增殖和成骨分化.     

缺氧环境对牙周膜成纤维细胞增殖及凋亡的影响

目的：研究缺氧环境对牙周膜成纤维细胞的增殖及凋亡相关蛋白表达的影响。方法采用氯化钴模拟法构建人牙周膜成纤维细胞缺氧模型。观察缺氧条件下牙周膜成纤维细胞形态变化,采用CCK-8检测细胞增殖情况,并用Western Blot方法检测凋亡相关因子p53、Bcl-2及caspase-7的表达变化。结果随着时间延长,缺氧组细胞数量减少,体积逐渐变小,细胞胞浆浓缩,细胞存活率降低。 Western Blot 结果显示缺氧组 p53、Bcl-2及caspase-7蛋白表达量随着缺氧时间延长逐渐升高。缺氧组p53蛋白、caspase-7表达高于常氧组,Bcl-2表达低于常氧组。结论缺氧环境可影响牙周膜成纤维细胞形态、增殖活性及凋亡相关蛋白的表达。     

低氧对牙周膜成纤维细胞增殖和成骨分化的影响

目的:观察低氧对体外培养的人牙周膜成纤维细胞(periodontal ligament cells, PDLCs)增殖与成骨分化的影响。方法:体外培养鉴定人牙周膜成纤维细胞,分别用浓度为0、100、200、400 μmol/L的CoCl2作用于细胞,采用MTT法观察CoCl2对PDLCs增殖的影响,运用实时定量PCR和Western免疫印迹技术检测CoCl2模拟低氧对PDLCs成骨分化的影响。采用SPSS13.0软件包对数据进行统计学分析。结果:免疫组化染色结果证实,培养细胞为牙周膜成纤维细胞。200 μmol/L及400 μmol/L的CoCl2均能抑制PDLCs的增殖及碱性磷酸酶、RUNX2、Ⅰ型胶原的表达,并呈剂量依赖性。结论:氯化钴模拟的低氧环境对PDLCs增殖及成骨分化具有抑制作用。     

机械牵张作用对牙周膜成纤维细胞增殖的影响

目的 :观察机械牵张作用对牙周膜成纤维细胞 (PDLFs)增殖能力的影响。方法 :用自行研制的细胞加载系统对PDLFs施以频率为 6次 /min(每次为 5s牵拉、5s松弛 ) ,幅度 12 %的牵张力 ,于加载 2 4、48、96h后 ,通过细胞计数、流式细胞仪检测观察PDLFs增殖能力的改变情况。结果 :在不同的时间点 ,加力组及对照组的细胞数均不断增加 ,在 48h及 96h时加力组结果明显高于对照组。流式细胞仪结果显示在不同时间点加力组处于DNA合成期的细胞数明显高于对照组。结论 :在对培养的人PDLFs施加频率为 6次 /min、幅度 12 %的牵张力时 ,对细胞的增殖起一定的促进作用     

缺氧对人牙周膜成纤维细胞增殖和超微结构影响的实验研究

目的:体外培养人牙周膜成纤维细胞(HPLFS),观察缺氧对其生长增殖能力的影响.方法: 分离培养 HPLFS,随机分为 21% O2对照组和10%、5%、2% O2缺氧组,采用四唑盐(MTT)比色法检测 HPLFS增殖情况,透射电镜下观察细胞超微结构改变.结果:MTT 法检测,与对照组比,12 h、24 h,缺氧对细胞增殖随缺氧程度呈依赖性增强,但重度缺氧(2% O2)24 h组具有统计学差异;48 h、72 h,重度缺氧组细胞增殖与对照组相比明显降低,差别具有统计学意义.透射电镜下,重度缺氧24 h细胞胞质内粗面内质网和线粒体明显增多,细胞突起增多;72 h细胞发生退变,溶酶体增多.结论:长期重度缺氧条件下,牙周膜的改建和修复功能降低,可能是高原牙周疾病多发、牙周组织破坏较重的重要原因.     

缺氧对人牙周膜成纤维细胞增殖和碱性磷酸酶活性的影响

目的:观察不同程度缺氧对人牙周膜成纤维细胞(HPLFS)增殖、分化的影响.方法:随机将HPLFS分为4组;210mL/LO2对照组、100、50、20mL/LO2缺氧组(轻中重缺氧组),用MTT法、碱性磷酸酶试剂盒分别检测HPLFS的增殖和碱性磷酸酶(ALP)的活性.结果:第24小时,重度缺氧可促进HPLFS细胞增殖,第48、72小时,重度缺氧则明显抑制r细胞增殖;中、重度缺氧对细胞碱性磷酸酶活性表达随缺氧时间则明显受到抑制.结论:缺氧时间、程度对HPDLFs增殖和ALP活性表达存在效应关系,长期中、重度缺氧不利HPLFS的生长及向成骨分化能力,提示牙周组织改建修复功能降低.     

氯化钴化学模拟低氧对牙周膜成纤维细胞增殖及凋亡的影响

目的:研究低氧对人牙周膜成纤维细胞(periodontal ligament cells,PDLCs)的增殖及低氧诱导因子1α (hypoxia-inducible factor-1α,HIF-1α)和Caspase-3表达的影响.方法:采用二氯化钴(cobalt chloride,CoCl2)模拟低氧作用于人PDLCs,用MTT法检测人PDLCs的活力,并通过荧光定量PCR和Western印迹观察低氧处理后人PDLCs中HIF-1α和Caspase-3的表达变化.采用SAS6.12软件包对所得数据进行统计学分析.结果:低氧使人PDLCs存活率降低,并呈浓度和时间依赖;低氧促进HIF-1α蛋白的表达,而HIF-1α mRNA的水平未见影响(P>0.05);低氧使Caspase-3mRNA及Caspase-3蛋白表达均上调.结论:低氧抑制人PDLCs增殖,这与低氧诱导HIF-1α表达,促进细胞凋亡有关.提示低氧在牙周炎发生和发展中起一定调控作用.     

雌激素受体β对牙周膜细胞骨向分化能力影响的研究

目的 研究小干扰RNA(small interfering RNA,siRNA)抑制人牙周膜成纤维细胞(human periodontal ligament fibroblast cell,HPLF)中雌激素受体β(estrogen receptor β,ERβ)后,对17β-雌二醇(E2)诱导的成骨能力的影响。方法 设计并合成针对ERβ基因siRNA的寡核苷酸序列,插入载体形成重组载体。重组载体经测序鉴定后,以脂质体法转染至HPLF细胞中,蛋白质印迹法及RT-PCR法检测转染前后ERβ的表达情况。鉴定后用1×10-7mol/L的17β-E2干预经ERβsiRNA转染的HPLF细胞和未经ERβsiRNA转染的HPLF细胞,测定细胞的碱性磷酸酶(alkaline phosphatase,ALP)活性和骨钙素(os-teocalcin,OCN)含量。结果 测序鉴定重组质粒后,蛋白质印迹法及RT-PCR结果 显示ERβsiRNA载体可特异地抑制HPLF细胞中ERβ的表达。经雌激素干预后,HPLF细胞ALP活性和OCN含量高于对照组(P<0.01),但ERβsiRNA载体稳定转染的HPLF细胞ALP活性和OCN含量与对照组相比没有显著性差异。结论 雌激素可能通过ERβ亚基促进人牙周膜成纤维细胞的骨向分化能力。     

血管内皮细胞对牙周组织细胞增殖的影响

目的：通过血管内皮细胞与牙周组织细胞复合培养模拟牙周组织再生环境,观察血管内皮细胞对牙周组织细胞增殖的作用规律,探讨血管内皮细胞对牙周组织修复再生的影响。方法：应用原代培养的血管内皮细胞,在Transwell嵌套中实现与人牙周膜成纤维细胞、牙龈成纤维细胞间的复合培养,分别于复合培养第2、4、6、8和10天,以细胞计数手段检测血管内皮细胞共存条件下2种牙周组织细胞的增殖情况,并与单独培养的2种牙周组织细胞作为对照,采用SPSS13.0软件包对数据进行统计学分析。结果：在血管内皮细胞存在条件下,2种牙周组织细胞的增殖速率均显著高于单独培养条件。血管内皮细胞存在时,牙周膜成纤维细胞增殖速率逐渐超越牙龈成纤维细胞(第6天起),并在第8天细胞数量上超过牙龈成纤维细胞,差异具有显著性(P<0.01)。结论：血管内皮细胞的存在,对牙周组织细胞的增殖具有促进作用,对牙周膜成纤维细胞增殖的促进作用显著高于牙龈成纤维细胞。     

Calcitonin induces collagen synthesis and osteoblastic differentiation in human periodontal ligament fibroblasts

BackgroundExtracellular matrix (ECM) secretion and osteogenic differentiation in periodontal ligament fibroblasts (PDLF) facilitate the neogenesis of alveolar bone, which is the cellular basis for alveolar bone repair. Calcitonin (CT) has been reported to play an important role in promoting ECM expression and inducing osteogenic differentiation in osteoblast, but its effects on PDLFs remain obscure.MethodsThe expression of CT, transforming growth factor-beta 1(TGF-β1) and bone morphogenetic protein (BMP) in gingival crevicular fluid (GCF) was measured by ELISA. The effects of CT on collagen synthesis and osteogenic differentiation in hPDLFs were investigated by using the primarily cultured hPDLFs infected with adenovirus carrying the CT gene. Gene expression was measured by quantitative PCR and western blot.ResultsThe expression of CT in gingival crevicular fluid (GCF) of patients with periodontitis was significantly higher than that of healthy subjects. In addition, CT expression correlated with the clinical indexes including probing pocket depth (PPD), clinical attachment level (CAL), and gingival index (GI). The in vitro study demonstrated that overexpression of CT by adenovirus infection increased the expression of TGF-β1, collagen type I and III, and osteoblastic markers including BMP-2/-4, alkaline phosphatase and osteocalcin in human PDLFs. Moreover, CT-enhanced collagen synthesis was abrogated in hPDLFs transfected with TGF-β1 siRNA, and CT-induced osteoblastic differentiation was blocked in hPDLFs by BMPs inhibitor noggin.ConclusionsThese results suggest that CT promotes collagen synthesis and osteogenic differentiation in hPDLFs via the TGF-β1 and BMPs signaling pathways, respectively.     

Effect of propolis on proliferation and apoptosis of periodontal ligament fibroblasts

The most critical factors affecting the prognosis of an avulsed tooth are extraoral dry time and storage media used before replantation. Studies have analyzed different storage media to determine the ideal solution to preserve periodontal ligament (PDL) cell viability. Propolis has anti-inflammatory and antimicrobial properties, and has been previously suggested as a storage medium. The purpose of this study was to assess not only cell viability but also physiological health of PDL cells after exposure to propolis. PDL cells were exposed to different concentrations of propolis or Hanks balanced salt solution, and the apoptotic levels were determined using apoptosis assay and flow cytometry. Additional cell viability and proliferation were analyzed by XXT assay in dry and wet conditions. Propolis not only decreased apoptosis but also increased the metabolic activity and proliferation of PDL cells. This study suggests that propolis is a suitable storage medium for avulsed teeth.     

Effect of estrogen receptor beta on the osteoblastic differentiation function of human periodontal ligament cells

OBJECTIVE: To investigate the effect of estrogen receptor beta (ERbeta) on osteoblastic differentiation function of human periodontal ligament (hPDL) cells by measuring the alkaline phosphatase (ALP) activity and the production of osteocalcin (OCN) in vitro. DESIGN: We employed a short interfering RNA (siRNA) technique to inhibit ERbeta expression in hPDL cells; the cells were cultured with a saturating concentration of 17beta-estradiol (10(-7)M). ALP activity was analysed by colorimetric assay using ALP kit and the amount of OCN was assessed by osteocalcin ELISA kit. RESULTS: It was shown that estradiol significantly enhanced the ALP activity and the production of OCN in hPDL cells. However, the ALP activity and the production of OCN in hPDL-siERbeta cells were not significantly changed after estradiol treatment. CONCLUSIONS: These results indicate that ERbeta may play important roles in estrogen-induced effects on osteoblastic differentiation function of PDL cells and estrogen influences the bone formation capacity of PDL cells mainly via ERbeta.     

Simvastatin promotes cell metabolism, proliferation, and osteoblastic differentiation in human periodontal ligament cells

BACKGROUND: Simvastatin is one of the cholesterol lowering drugs. Recent studies demonstrated that it has a bone stimulatory effect. Periodontal ligament (PDL) cells are believed to play an important role in periodontal regeneration; that is, they may differentiate into specific cells which make cementum, bone, and attachment apparatus. It would be of interest whether simvastatin has a positive effect on PDL cells. Therefore, effects of simvastatin on cell proliferation and osteoblastic differentiation in PDL cells were analyzed. METHODS: Human PDL cells were cultured in monolayer with simvastatin for 24 and 72 hours and cell metabolism and proliferation were determined. To analyze osteoblastic differentiation, human PDL cells were cultured in organoid culture for 7, 14, and 21 days and alkaline phosphatase (ALP) activity, osteopontin (OPN), bone morphogenetic protein (BMP) -2, osteocalcin (OCN), and calcium contents were measured. They were co-treated by simvastatin and mevalonate. RESULTS: Simvastatin enhanced cell proliferation and metabolism dose-dependently after 24 hours. Simvastatin also stimulated ALP activity of human PDL cells dose-dependently, and maximum effect was obtained at the concentration of 10(8) M. In time dependent analysis, 10(8) M simvastatin stimulated ALP activity and osteopontin content after 7 days and calcium contents after 21 days. BMP-2 and OCN contents were not detected. Moreover this statin-enhanced ALP activity was abolished by mevalonate. CONCLUSION: These results suggest that at low concentration, simvastatin exhibits positive effect on proliferation and osteoblastic differentiation of human PDL cells, and these effects may be caused by the inhibition of the mevalonate pathway.     

IL-6 induces osteoblastic differentiation of periodontal ligament cells

Interleukin (IL)-6 has been considered as an osteolytic factor involved in periodontal disease. However, the function of IL-6 in osteoblastic differentiation of periodontal ligament cells is not clear. We examined the effects of IL-6 and its soluble receptor (sIL-6R) on osteoblastic differentiation of periodontal ligament cells. Osteoblastic differentiation was induced by ascorbic acid. Osteoblast markers, including alkaline phosphatase activity and Runx2 gene expression, were examined. The mechanism of action of IL-6 on osteoblastic differentiation was evaluated by insulin-like growth factor (IGF)-I production and specific inhibitors for the IL-6-signaling molecule. IL-6/sIL-6R enhanced alkaline phosphatase activity and Runx2. Alkaline phosphatase activity was reduced by anti-IGF-I antibody. Mitogen-activated protein kinase and Janus protein tyrosine kinase inhibitors diminished alkaline phosphatase induced by IL-6/sIL-6R. We conclude that IL-6/sIL-6R increases ascorbic-acid-induced alkaline phosphatase activity through IGF-I production, implying that IL-6 acts not only as an osteolytic factor, but also as a mediator of osteoblastic differentiation in periodontal ligament cells.     

人牙周膜细胞和牙龈成纤维细胞生物学活性的研究

目的:体外原代培养人牙周膜细胞和牙龈成纤维细胞,并对其生物学活性作初步探讨.方法:采用组织块法原代培养牙周膜细胞和牙龈成纤维细胞,绘制生长曲线,测定二者碱性磷酸酶活性;流式细胞术和免疫组化染色法测定Ⅰ、Ⅲ型胶原、骨形成蛋白的表达情况,观察对比两种细胞的生物学特性的异同.结果:牙龈成纤维细胞原代培养成功率及细胞增殖活性明显高于牙周膜细胞.在牙周膜细胞中,Ⅰ、Ⅲ型胶原均为阳性表达,棕黄色颗粒克满整个胞浆内.在牙龈成纤维细胞中Ⅰ型胶原为弱阳性表达,Ⅲ型胶原阳性表达更弱.牙周膜细胞的ALP水平明显高于牙龈成纤维细胞.牙周膜细胞BMP2表达为强阳性,而牙龈成纤维细胞表达弱阳性.结论:牙周膜细胞具有较强的成骨能力,是理想的牙周组织工程的种子细胞.牙龈成纤维细胞易于培养成活,增殖力强,具有牙周膜细胞的一些特点,组织取材方便,也可作为牙周组织工程的种子细胞.     

人牙周膜成纤维细胞增殖与压力关系的初步观察

目的：在体外培养环境下观察压力对人牙周膜成纤维细胞（HPLF）增殖的影响。方法：取第4－6代培养的HPLF,应用可控压力细胞加载装置分别间断性施加30、60、90kPa的压力,分别在培养3、5、7d后用MTT法测定各组的A值。结果：HPLF在30、60、90kPa的压力培养环境下MTT反应的A值显著小于对照组,压力值越大,A值越小。结论：30、60、90kPa间断性压力显著抑制PLF细胞增殖,该抑制作用随压力值增大而增强。     

Differential responsiveness against mechanical stress between osteoblastic cells and periodontal ligament cells

Using the human osteosarcoma-derived osteoblastic cell line, HOS cells, and the human periodontal ligament-derived fibroblast-like cells (Periodontal ligament cells; PDL cells), we examined the responsiveness against mechanical stress (continuously applied compressive force) in HOS and PDL cellsin vitro. SDS-PAGE revealed that loading of mechanical stress (10 g/cm²) promoted intracellular protein production (approx. 30–35 kDa, 40kDa, 55kDa, 65–70kDa) in HOS cells, which are different sizes from those in PDL cells reported previously. Mechanical stress also enhanced heat shock protein (HSP) production in HOS cells and PDL cells: however, the responsiveness was different between HOS cells and PDL cells. In PDL cells, mechanical stress enhanced HSP 60 production more efficiently, in contrast that HSP 70 production was promoted more efficiently in HOS cells. These data suggest that differential responsiveness against mechanical stress between osteoblasts and PDL cells might have important role during orthodontic tooth movement.

     

乏氧对人牙周膜细胞增殖和碱性磷酸酶活性表达的影响

目的: 探讨不同氧张力对牙周膜细胞的增殖碱性磷酸酶活性(alkaline phosphatase activity,ALP)影响.方法:采用组织块法体外培养人牙周膜细胞,取第5代培养细胞分别在210 mL/L(对照组)和10mL/LO2浓度(乏氧组)下培养1～3 d,复氧组在相同的乏氧环境下培养1 d和2 d后分别移到常氧条件下继续培养1～2 d后检测牙周膜细胞增殖能力与分泌碱性磷酸酶情况.结果:所有组别的细胞增殖率随培养时间呈依赖性的增高.乏氧组乏氧第2,3 d与对照组有统计学差异.所有组别细胞的ALP活性随时间而降低,但乏氧第1,2,3天和复氧1 d与对照组相比明显降低,差别具有统计学意义.结论:乏氧对牙周膜细胞的生物学有较大的影响,提示临床牙周炎及正畸所导致的缺氧环境对牙周膜细胞活性与功能有一定的影响.     

复方奥硝唑缓释牙栓对人牙周膜成纤维细胞生长的影响

目的：观察复方奥硝唑甲磺酸培氟沙星缓释牙栓对体外培养的人牙周膜成纤维细胞（HPDLFS）生长的影响。方法：采用组织块法培养HPDLFS,观察缓释牙栓在0、0.1、0.5、2.5、10、50、200g/L对体外培养HPDLFS蛋白合成及DNA合成的影响,MTT法检测细胞在6、12、24、48、72h光密度值（OD）,计算细胞相对增殖率（RGR）。结果：免疫组化试验证实;不同浓度缓释牙栓对HPDLFS蛋白合成及DNA合成与对照组相比无显著性差异（p〉0.05）;随作用时间、浓度不同,HPDLFS生长趋势稳定,RGR均在90%以上。结论：在200g/L缓释浓度范围内,该缓释牙栓有较佳的生物相容性,未显示有细胞抑制作用。