人牙龈和牙周韧带成纤维细胞体外矿化能力的比较研究

目的：研究人牙龈和牙周韧带成纤维细胞体外矿化能力的差异。方法：用组织块法培养同一患者的牙龈和牙周韧带成纤维细胞，取第4-8代细胞用矿化培养液长期培养，倒置显微镜下观察矿化情况，von Kos-sa染色显示钙盐沉积，生化法测定各组碱性磷酸酶活性，扫描电镜及X线能谱法分析矿化结节中钙磷比例。结果：倒置显微镜下观察牙周韧带成纤维细胞可呈复层生长，形成肉眼可见的白色结节，von Kossa染色显示结节内有钙盐沉积，碱性磷酸酶活性测定表明随着矿化培养时间的延长牙周韧带成纤维细胞组ALP活性比牙龈成纤维细胞组增高明显，扫描电镜下表明结节处电子反射增强，X射线能谱分析显示钙化结节内的钙磷比例与矿化组织相似；牙龈成纤维细胞及对照组体外不能形成钙化结节。结论：人牙龈和牙周韧带成纤维细胞体外矿化能力不同。     

人牙周膜成纤维细胞在无血清培养液中的生长特性

目的：探讨人牙周膜成纤维细胞在无血清培养液中的生长特性。方法：用倒置显微镜和MTT法观察人牙周膜成纤维细胞在无血清培养液中的生长和增殖变化。结果：人牙周膜成纤维细胞在无血清培养条件下可以生长的增殖，但与含血清培养液相比，其增殖速率变缓，分化明显。结论：无血清培养液可应用于人牙周膜成纤维细胞的体外培养和实验研究中。     

Prostaglandin E2 and I2 regulate intercellular adhesion molecule-1 expression in interleukin-1 beta-stimulated human gingival fibroblasts

The present study investigated the effect of prostaglandin (PG) E₂ and PGI₂ on intercellular adhesion molecule-1 (ICAM-1) expression in interleukin-1β (IL-1β)-stimulated human gingival fibroblasts (HGF). IL-1β potently induced ICAM-1 expression in HGF and indomethacin, a cyclooxygenase inhibitor, enhanced ICAM-1 expression in the cells. These data showed that endogenous PGs generated by HGF stimulated with IL-1β downregulated ICAM-1 expression. IL-1β significantly increased the levels of PGE₂ and, to a lesser extent, those of 6-keto-PGF_1α (a stable metabolite of PGI₂) in the culture media of HGF. Indomethacin completely inhibited the production of PGE₂ and 6-keto-PGF_1α in IL-1β-stimulated HGF. Exogenous PGE₂ and carbacyclin (a stable derivative of PGI₂) in the presence of indomethacin dose-dependently suppressed ICAM-1 expression in IL-1β-challenged HGF. Since PGE₂ and PGI₂ are known to elevate intracellular cyclic AMP (cAMP) levels, we examined the effect of dibutyryl cAMP, a cAMP analogue, and isobutylmethylxanthine, a phosphodiesterase inhibitor, on ICAM-1 expression. Both agents downregulated ICAM-1 expression in IL-1β-stimulated HGF. These results suggest that PGE₂ and PGI₂ downregulate ICAM-1 expression in IL-1β-stimulated HGF through a cAMP-dependent mechanism and that intracellular cAMP elevation in HGF may control inflammatory and immune responses in periodontal disease.     

Mineralized nodule formation by cultures of human dental pulp-derived fibroblasts

Pulp fibroblasts were isolated from human deciduous and supernumerary teeth and cultured in vitro. With continued culture in normal tissue-culture medium, six pulp fibroblast strains formed cell nodules after 10–15 days. By electron microscopy the nodules had matrix vesicles, and needle-shaped crystals associated with a dense network of collagen fibrils. The crystalline material exhibited a pattern consistent with hydroxyapatite when nodules were examined by X-ray diffractometry. Furthermore, the cells showed high levels of alkaline phosphatase activity, which could be increased more than seven-fold by the addition of 1,25(OH)₂D₃ (5 × 10⁻⁹−5 × 10⁻⁸M). In addition to the production of type I collagen, these cells also synthesized fibronectin and osteonectin. The formation of mineralized tissue nodules by pulp cells in vitro provides a useful system for study of the pathological calcification of pulp tissues.     

Human gingival fibroblasts function is stimulated on machined hydrided titanium zirconium dental implants

Objectives

The aim of this study was to evaluate the influence of different titanium zirconium (TiZr) alloy surfaces on primary human gingival fibroblasts (HGF) for improved soft tissue integration of dental implants.

Methods

TiZr polished, machined and machined + HCl/H₂SO₄ acid-etched surfaces were modified by cathodic polarization and/or HNO₃/HF acid etching. Contact angle of surfaces was measured. The influence of modified TiZr surfaces on HGF was evaluated through the analysis of cell number, morphology, recovery after a wound (wound healing assay) and the expression of several genes, including matrix metalloproteinase-1 (MMP1) and metallopeptidase inhibitor-1 (TIMP1).

Results

Modification of TiZr surfaces decreased its hydrophilicity. Hydride implementation on TiZr surfaces via cathodic polarization increased TIMP1 expression and decreased MMP1/TIMP1 mRNA ratio. Cathodic polarization of machined surfaces promoted cell attachment. Cells on machined and machined + cathodic polarization surfaces grew aligned to the microgrooves whereas on all polished surfaces they grew randomly. Acid etching of polished and machined surfaces did not improve HGF function.

Conclusions

Hydride implementation on TiZr machined surfaces may be used as new dental implant material for improved soft tissue integration.

Clinical significance

Enhancing dental implant surfaces’ bioactivity by hydride implementation may promote soft tissue attachment and sealing around the implant and reduce peri-implantitis related to ECM-destruction compared with conventional machined surfaces.     

MMP-3诱导人牙髓成纤维细胞CCN2mRNA的表达及意义

目的：通过观察基质金属蛋白酶-3（MMP-3）对体外培养人牙髓成纤维细胞中结缔组织生长因子（CTGF/CCN2）mRNA的影响,揭示MMP-3促进牙髓损伤愈合的机制。方法：选取年轻患者因正畸或阻生拔除的健康第三磨牙,取出牙髓以常规体外酶消化培养法获得人牙髓成纤维细胞,利用RT-PCR方法检测经MMP-3诱导30min后人牙髓成纤维细胞中CCN2mRNA的表达。结果：正常组和实验组人牙髓成纤维细胞均有CCN2mRNA表达,但是经MMP-3诱导后的人牙髓成纤维细胞CCN2mRNA的表达更强。结论：MMP-3通过诱导CCN2mRNA的合成,从而促进牙髓损伤的愈合。     

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目的 探讨双氯芬酸钠对脂多糖（LPS）诱导的人牙周膜成纤维细胞（HPDLFs）白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）表达的影响。方法 本研究于2013年3—5月在山西医科大学口腔实验室进行。将复苏培养冻存的HPDLFs进行形态学鉴别后,用10 μg/mL的LPS进行诱导,分别以0.1、1、10、50、100 mg/L的双氯芬酸钠进行干预,酶联免疫吸附试验法（ELISA法）检测HPDLFs表达IL-1β和TNF-α水平的变化。结果 对同一质量浓度LPS诱导的HPDLFs而言,双氯芬酸钠能下调HPDLFs表达IL-1β和TNF-α的水平,并且随着双氯芬酸钠质量浓度的增加,IL-1β和TNF-α的表达量呈逐渐减弱的趋势（P＜0.05）。结论 双氯芬酸钠可能对于LPS诱导的HPDLFs IL-1β和TNF-α的表达有重要的抑制作用,这为牙周病的临床治疗提供了新的思路。