体外培养的人牙髓细胞、牙周韧带细胞几种基质表达和碱性磷酸酶分泌的研究

目的：研究并比较培养的５～７代人牙髓细胞和牙周韧带细胞几种基质表达和碱性磷酸酶分泌的情况。方法：细胞培养、免疫组化、碱性磷酸酶活性分析。结果：两种细胞均在培养的第９天进入生长静止期，两种细胞培养液中碱性磷酸酶活性在增殖期达到高峰，以后活性下降。两种细胞均表达ＦＮ、Ⅲ型胶原、ＢＭＰ。当培养的细胞密度较高时，ＦＮ和Ⅲ型胶原以纤维状结构覆盖于细胞表面。结论：传代的人牙髓细胞和牙周韧带细胞的上述几种基质表达方式、碱性磷酸酶活性相似。     

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.     

釉基质蛋白在牙髓细胞增殖中的作用

目的探讨釉基质蛋白对牙髓细胞增殖的作用及其机理。方法分离培养人的牙髓细胞,加入不同浓度的Emdogain,采用化学发光免疫测定方法比较牙髓细胞的生长情况,采用Superarray方法研究加入Emdogain对细胞周期相关因子的影响。结果牙髓细胞在不同浓度的Emdogain作用下呈现不同的生长速率。Emdogain促进牙髓细胞生长的最佳浓度为300μg/ml。细胞周期相关因子的Superarray分析显示,Emdogain通过上调cyclin D1,p21,E6-AP,SUMO-1基因达到对细胞生长的促进作用。结论适宜浓度的Emdogain（45～600μg/ml）能够促进牙髓细胞的增殖。     

Immunolocalization of bone extracellular matrix proteins (type I collagen,osteonectin and bone sialoprotein) in human dental pulp and cultured pulp cells

AIM: To simultaneously analyse the expression of type I collagen, osteonectin and bone sialoprotein (BSP) in human dental pulp of different ages. METHODOLOGY: Cultured dental pulp fibroblasts (FP1 cell line), pulps from dental germs with incomplete root formation (n = 4) and pulps of erupted teeth with total root formation (n = 4) were used. Bone proteins were searched by immunohistochemistry and immunofluorescence using polyclonal antibodies and compared among the three groups assessed. RESULTS: Immunohistochemistry detected the three proteins in dental pulp tissue, as it labelled extracellular matrix, predentine and odontoblasts. The BSP label was weaker, when compared to both type I collagen and osteonectin. The presence of type I collagen was more evident in pulps from erupted teeth, when compared to germ dental pulps. On the other hand, a strong expression of osteonectin in germ dental pulps was observed. CONCLUSIONS: Regardless of the degree of maturation, dental pulps present type I collagen, osteonectin and BSP in the extracellular matrix (ECM) and in the odontoblastic layer. Thus, the results suggest that these proteins are related to the production and mineralization of dentine.     

釉基质蛋白对人牙髓细胞成牙本质分化的影响

目的 探讨釉基质蛋白对人牙髓细胞(human dental pulp cells,HDPC)成牙本质分化的影响,为牙本质的组织工程学研究提供有效的生物活性物质.方法 将HDPC接种于6孔板(2×105个/孔)后分为5组,分别加入含1、10、100 mg/L釉基质蛋白(enamel matrix proteins,EMP)(分别为EMP 1、10、100 mg/L组)、10-8 mol/L地塞米松及100 mg/L抗坏血酸(dexamethasone and ascorbic acid,Dex-AA组)、单纯基础培养液(对照组).于培养1、5、10 d分别用碱性磷酸酶(alkaline phosphatase,ALP)试剂盒检测ALP活性,实时荧光定量反转录聚合酶链反应技术检测成牙本质相关基因牙本质基质蛋白1(dentine matrix protein-1,DMP-1)及牙本质涎磷蛋白(dentine sialophosphoprotein,DSPP)的表达,应用2-△△CT方法得出具体数值并进行单因素方差分析与Post Hoe 检验,用茜素红染色检测并定量分析矿化情况.结果 各组ALP水平呈时间依赖性上调,培养1d后各组ALP活性与对照组相比差异均无统计学意义;5 d后EMP 10、100 mg/L组及Dex-AA组ALP活性显著增高,分别达到7.573±0.267、6.119±0.502、5.846±0.096,与对照组相比差异均有统计学意义(P＜0.05);10 d后10 mg/L EMP组及Dex-AA组ALP活性增高更显著,分别达21.035±0.149、13.223±0.797,与对照组(5.825±0.404)相比差异均有统计学意义(P＜0.01).培养1d后各组DMP-1及DSPP mRNA水平均较对照组显著升高,差异均有统计学意义(P＜0.01);培养10 d后10 mg/L EMP组DMP-1和DSPP表达水平均显著增高,分别达到14.791±0.164、12.238±0.421.培养10 d后各组均有矿化,10 mg/L EMP组钙离子浓度[(191.8±2.0) μmol/L]显著高于对照组[(81.1±8.1)μmol/L],差异有统计学意义(P＜0.01).结论 适当浓度的EMP对HDPC的成牙本质分化有一定的促进作用.     

Effect of fluocinolone acetonide on human dental pulp cells: cytotoxicity, proliferation, and extracellular matrix formation

Introduction

The goal of vital pulp therapy is to maintain pulp vitality and function. Fluocinolone acetonide is a potent topical glucocorticoid used in the treatment of skin disorders and oral lesions that could possibly be used to resolve inflammation and stimulate the healing process of inflamed dental pulp. The purpose of this study was to investigate the effects of fluocinolone acetonide (0.1-50 μmol/L) on cytotoxicity, cell proliferation, and fibronectin and type I collagen synthesis in human dental pulp cells (HDPCs).

Methods

HDPCs were prepared from freshly extracted human third molars. MTT assay was used to determine toxicity and cell proliferation. Western blot analysis was performed to detect fibronectin and type I collagen synthesis.

Results

Low concentrations of fluocinolone acetonide were not only nontoxic but also significantly stimulated cell proliferation (P < .05). Fluocinolone acetonide significantly stimulated fibronectin and type I collagen synthesis (P < .05).

Conclusions

Low concentrations (0.1-10 μmol/L) of fluocinolone acetonide might have the potential to stimulate healing of inflamed dental pulp.     

The effect of extracellular calcium ion on gene expression of bone-related proteins in human pulp cells

Calcium hydroxide is often used for induction of reparative dentin formation in endodontic treatment. However, little is known about the mechanism by which calcium hydroxide works. The calcium ion (Ca2+) is an important regulator of cell functions. In this study, we examined the effect of extracellular Ca2+ on gene expression of bone-related proteins in human cultured pulp cells in serum-free conditions. A Ca2+ level elevated by 0.7 mM induced an increase in mRNA expression of osteopontin and bone morphogenetic protein (BMP)-2. However, mRNA levels of BMP-4 and alkaline phosphatase decreased under the elevated Ca2+ culture condition. The same concentration of additional magnesium ions had little effect on expressions of the examined bone-related protein mRNAs. These findings suggest that Ca2+ in Ca(OH)2 specifically modulates osteopontin and BMP-2 levels during calcification in pulp.     

Anaerobic bacterial extracts influence production of matrix metalloproteinases and their inhibitors by human dental pulp cells

The role of human dental pulp (HDP) cells in extracellular matrix degradation in pulpitis is still unclear. In this study, the effects of sonicated bacterial extracts (SBEs) from Prevotella intermedia, Fusobacterium nucleatum, Porphyromonas endodontalis, and Porphyromonas gingivalis on the balance between the production of matrix metalloproteinases (MMPs) and that of their inhibitors [tissue inhibitors of metalloproteinases (TIMPs)] by HDP cells were examined. HDP cells were treated with SBEs, and their culture media were later harvested. MMP activities and TIMP concentrations were determined by use of independent measurement strategies and sensitive ELISAs. The production of MMP-1 and MMP-2 was accelerated by all SBE. On the other hand, TIMP-1 production was slightly elevated; and TIMP-2 production was markedly inhibited by all of the extracts. SBEs derived from these anaerobic bacteria seemed to affect the acceleration of extracellular matrix degradation activity by HDP cells. These findings suggest that HDP cells stimulated by bacterial byproducts may be involved in the pathogenesis of pulpitis.     

细胞外基质PDMS硬度对牙髓干细胞增殖和成骨分化的影响

目的:研究细胞外基质聚二甲基硅氧烷(polydimethylsiloxane,PDMS)硬度对牙髓干细胞(DPSCs)增殖和成骨分化的影响及其机制.方法:收集南京医科大学附属常州市第二人民医院因正畸而拔除的前磨牙作为实验材料,分离、培养DPSCs,制作PDMS基质.根据不同硬度,将PDMS基质分为A组(基料/固化剂=1...     

Estradiol induces osteoprotegerin expression by human dental pulp cells

Estrogen deficiency is associated with increased inflammation related periapical bone resorption. The present study aimed to evaluate the effect and intracellular mechanism(s) of estrogen on osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) expression in human dental pulp cells (HDPs). HDPs were treated with estradiol at a concentration of 0.1–10 μM. The results showed that estradiol induced OPG expression at both the mRNA and protein levels in a dose-dependent manner. However, no influence on RANKL expression was observed. An estrogen receptor (ER) inhibitor failed to attenuate the estradiol-induced OPG expression. Furthermore, ER-α and ER-β agonists did not simulate estradiol’s effects on OPG expression by HDPs. However, a significant OPG upregulation was observed in HDPs treated with an estradiol-BSA conjugate or a GPR30 agonist. An ERK inhibitor significantly enhanced estradiol-induced OPG expression, whereas a p38 inhibitor markedly attenuated this expression. In conclusion, OPG expression by HDPs may be regulated by estradiol binding a membrane receptor and the balance between the ERK and p38 signaling pathways.     

体外培养人牙周牙髓相关细胞中釉原蛋白的表达

目的:观察釉原蛋白(amelogenin,Am)基因在体外培养的人牙龈上皮细胞及口腔外胚间充质来源细胞(人牙龈成纤维细胞、人牙周膜成纤维细胞和人牙髓细胞)中的表达.方法:采用反转录多聚酶链式反应(RT-PCR)技术,检测培养细胞中釉原蛋白mRNA的表达.采用蛋白质免疫印迹技术检测培养细胞中釉原蛋白的表达.结果:培养的人牙周膜成纤维细胞、牙髓细胞、牙龈成纤维细胞和牙龈上皮细胞中均未检测到釉原蛋白及其mRNA的表达.结论:体外培养的人牙周膜成纤维细胞、牙髓细胞、牙龈成纤维细胞和牙龈上皮细胞不表达釉原蛋白基因.     

Smad2、3在人牙髓组织中的表达及意义

目的：观察转化生长因子β特异的细胞内信号转导分子Smad2、3在牙髓组织中的表达及其变化,探讨Smad2、3在牙髓损伤修复中的作用。方法：用免疫组化方法检测Smad2、3在正常、龋坏及炎症牙髓组织中的表达。结果：Smad2,3在正常和龋环牙髓的成本本质细胞层呈强阳性表达,在下方的多细胞区及中心部牙髓有阳性或弱阳性表达,炎症牙随浸润的炎细胞中Smad2、3呈强阳性表达,各类牙髓中Smad2的表达较Smad3略强。结论：Smad2、3在正常、龋坏及炎症牙髓组织中有表达,提示Smad2、3可能在TGF－β调节牙髓细胞增殖、分化的信号转导途径中发挥一定的作用。     

Stem cell properties of human dental pulp stem cells

In this study, we characterized the self-renewal capability, multi-lineage differentiation capacity, and clonogenic efficiency of human dental pulp stem cells (DPSCs). DPSCs were capable of forming ectopic dentin and associated pulp tissue in vivo. Stromal-like cells were reestablished in culture from primary DPSC transplants and re-transplanted into immunocompromised mice to generate a dentin-pulp-like tissue, demonstrating their self-renewal capability. DPSCs were also found to be capable of differentiating into adipocytes and neural-like cells. The odontogenic potential of 12 individual single-colony-derived DPSC strains was determined. Two-thirds of the single-colony-derived DPSC strains generated abundant ectopic dentin in vivo, while only a limited amount of dentin was detected in the remaining one-third. These results indicate that single-colony-derived DPSC strains differ from each other with respect to their rate of odontogenesis. Taken together, these results demonstrate that DPSCs possess stem-cell-like qualities, including self-renewal capability and multi-lineage differentiation.