目的研究硒对小鼠氟斑牙发生的拮抗作用,并检测其对自噬相关基因Beclin1表达的影响。方法将36只2月龄费城癌症研究所(institute of cancer research,ICR)雄鼠,随机分为3组,每组12只,建立饮水型氟斑牙模型,用亚硒酸钠(Na2SeO3)进行干预,...目的研究硒对小鼠氟斑牙发生的拮抗作用,并检测其对自噬相关基因Beclin1表达的影响。方法将36只2月龄费城癌症研究所(institute of cancer research,ICR)雄鼠,随机分为3组,每组12只,建立饮水型氟斑牙模型,用亚硒酸钠(Na2SeO3)进行干预,具体分组为:对照组(ddH2O)、氟化钠组(200 mg/L NaF)、硒组(2 mg/L Na2SeO3+200 mg/L NaF),喂养8周后,观察氟斑牙发生情况,记录其长度并计算小鼠下颌切牙增长率;分离下颌骨后,进行micro-CT扫描,测量小鼠切牙唇侧硬组织厚度;H-E染色观察成釉细胞的变化,免疫组化方法检测Beclin1的表达。结果氟化钠组氟斑牙检出率为100%,表现为小鼠切牙白垩色改变;硒组未发现明显氟斑牙症状,形态与色泽介于正常与极轻度之间;micro-CT结果显示,氟化钠组切牙唇侧硬组织厚度比对照组薄,硒组介于两者之间(P<0.01);H-E结果显示,氟化钠组成釉细胞排列紊乱,极性消失;而对照组与硒拮抗组成釉细胞呈栅栏状,排列整齐规则;免疫组化结果显示,3组中成釉细胞从分泌期到成熟期Beclin1的阳性表达均呈逐渐增强的表达趋势,且Beclin1在氟化钠组表达明显强于正常组,硒组介于两者之间。结论2 mg/L硒离子浓度对氟斑牙的发生有一定拮抗作用;其作用机制可能是通过抑制成釉细胞自噬的发生,进而减轻过量氟对小鼠切牙毒性影响。展开更多
The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines （ENAMEL） Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National institute of Dental and Craniofacial Research （NI...The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines （ENAMEL） Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National institute of Dental and Craniofacial Research （NIDCR）. Discussion topics included model organisms, stem cells/cell lines, and tissues/3D cell culture/organoids. Scientists from a number of disciplines, representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field.展开更多
Tooth crown morphogenesis is tightly regulated by the proliferation and differentiation of dental epithelial cells. Globoside （Gb4）, a globo-series glycosphingolipid, is highly expressed during embryogenesis as well...Tooth crown morphogenesis is tightly regulated by the proliferation and differentiation of dental epithelial cells. Globoside （Gb4）, a globo-series glycosphingolipid, is highly expressed during embryogenesis as well as organogenesis, including tooth development. We previously reported that Gb4 is dominantly expressed in the neutral lipid fraction of dental epithelial cells. However, because its functional role in tooth development remains unknown, we investigated the involvement of Gb4 in dental epithelial cell differentiation. The expression of Gb4 was detected in ameloblasts of postnatal mouse molars and incisors. A cell culture analysis using HAT-7 cells, a rat-derived dental epithelial cell line, revealed that Gb4 did not promote dental epithelial cell proliferation. Interestingly, exogenous administration of Gb4 enhanced the gene expression of enamel extracellular matrix proteins such as ameloblastin, amelogenin, and enamelin in dental epithelial cells as well as in developing tooth germs. Gb4 also induced the expression of TrkB, one of the key receptors required for ameloblast induction in dental epithelial cells. In contrast, Gb4 downregulated the expression of p75, a receptor for neurotrophins （including neurotrophin-4） and a marker of undifferentiated dental epithelial cells. In addition, we found that exogenous administration of Gb4 to dental epithelial cells stimulated the extracellular signal-regulated kinase and p38 mitogen-activated protein kinase signalling pathways. Furthermore, Gb4 induced the expression of epiprofin and Runx2, the positive regulators for ameloblastin gene transcription. Thus, our results suggest that Gb4 contributes to promoting the differentiation of dental epithelial cells into ameloblasts.展开更多
This study aimed to compare epithelial cells derived from human embryonic stem cells(hESCs) to human ameloblast-lineage cells (ALCs),as a way to determine their potential use as a cell source for ameloblast regenerati...This study aimed to compare epithelial cells derived from human embryonic stem cells(hESCs) to human ameloblast-lineage cells (ALCs),as a way to determine their potential use as a cell source for ameloblast regeneration.Induced by various concentrations of bone morphogenetic protein 4(BMP4),retinoic acid(RA) and lithium chloride(LiCI) for 7 days,hESCs adopted cobble-stone epithelial phenotype(hESC-derived epithelial cells(ES-ECs)) and expressed cytokeratin 14.Compared with ALCs and oral epithelial cells(OE), ES-ECs expressed amelogenesis-associated genes similar to ALCs.ES-ECs were compared with human fetal skin epithelium,human fetal oral buccal mucosal epithelial cells and human ALCs for their expression pattern of cytokeratins as well.ALCs had relatively high expression levels of cytokeratin 76,which was also found to be upregulated in ES-ECs.Based on the present study,with the similarity of gene expression with ALCs,ES-ECs are a promising potential cell source for regeneration,which are not available in erupted human teeth for regeneration of enamel.展开更多
文摘The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines （ENAMEL） Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National institute of Dental and Craniofacial Research （NIDCR）. Discussion topics included model organisms, stem cells/cell lines, and tissues/3D cell culture/organoids. Scientists from a number of disciplines, representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field.
基金supported by JSPS KAKENHI from the Japan Society for the Promotion of Science and the Ministry of Education (15H05032 and 15K15752 to Takashi Nakamura and 26253092 to Satoshi Fukumoto)
文摘Tooth crown morphogenesis is tightly regulated by the proliferation and differentiation of dental epithelial cells. Globoside （Gb4）, a globo-series glycosphingolipid, is highly expressed during embryogenesis as well as organogenesis, including tooth development. We previously reported that Gb4 is dominantly expressed in the neutral lipid fraction of dental epithelial cells. However, because its functional role in tooth development remains unknown, we investigated the involvement of Gb4 in dental epithelial cell differentiation. The expression of Gb4 was detected in ameloblasts of postnatal mouse molars and incisors. A cell culture analysis using HAT-7 cells, a rat-derived dental epithelial cell line, revealed that Gb4 did not promote dental epithelial cell proliferation. Interestingly, exogenous administration of Gb4 enhanced the gene expression of enamel extracellular matrix proteins such as ameloblastin, amelogenin, and enamelin in dental epithelial cells as well as in developing tooth germs. Gb4 also induced the expression of TrkB, one of the key receptors required for ameloblast induction in dental epithelial cells. In contrast, Gb4 downregulated the expression of p75, a receptor for neurotrophins （including neurotrophin-4） and a marker of undifferentiated dental epithelial cells. In addition, we found that exogenous administration of Gb4 to dental epithelial cells stimulated the extracellular signal-regulated kinase and p38 mitogen-activated protein kinase signalling pathways. Furthermore, Gb4 induced the expression of epiprofin and Runx2, the positive regulators for ameloblastin gene transcription. Thus, our results suggest that Gb4 contributes to promoting the differentiation of dental epithelial cells into ameloblasts.
基金supported by NIH/NIDCR grants R03 DE019507-02 to Yan Zhang,R21 D E0 18633 to Pamela K DenBesten and 2011SCU 11999-3/ NSFC81200760to Li-Wei Zheng
文摘This study aimed to compare epithelial cells derived from human embryonic stem cells(hESCs) to human ameloblast-lineage cells (ALCs),as a way to determine their potential use as a cell source for ameloblast regeneration.Induced by various concentrations of bone morphogenetic protein 4(BMP4),retinoic acid(RA) and lithium chloride(LiCI) for 7 days,hESCs adopted cobble-stone epithelial phenotype(hESC-derived epithelial cells(ES-ECs)) and expressed cytokeratin 14.Compared with ALCs and oral epithelial cells(OE), ES-ECs expressed amelogenesis-associated genes similar to ALCs.ES-ECs were compared with human fetal skin epithelium,human fetal oral buccal mucosal epithelial cells and human ALCs for their expression pattern of cytokeratins as well.ALCs had relatively high expression levels of cytokeratin 76,which was also found to be upregulated in ES-ECs.Based on the present study,with the similarity of gene expression with ALCs,ES-ECs are a promising potential cell source for regeneration,which are not available in erupted human teeth for regeneration of enamel.
