Enamelysin processing mechanisms in amelogenesis

釉质形成中的釉质溶解加工机制

基本信息

批准号：
9225454
负责人：
JOHN D BARTLETT
金额：
$ 2.52万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-16 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9225454
关键词：
Enamelysin processing mechanisms amelogenesis

项目摘要

Principal Investigator/Program Director (Last, first, middle): Bartlett, John, D. The goal of this application is to characterize the role of matrix metalloproteinase-20 (MMP20) and N- cadherin in ameloblast movement and cell-cell attachment during dental enamel development. MMP20 is essential for dental enamel formation. People and mice lacking functional MMP20 have strikingly malformed dental enamel that is thin, soft, and easily abrades from the underlying dentin. In Mmp20 null mice, the secretory stage ameloblasts do not enter the maturation stage of development properly and, once there, the ameloblasts overlap and grow atop one another. This suggests that ameloblast cell-cell attachment and signaling is altered in Mmp20 null mice. Cadherins are a family of proteins that span the cell membrane mediating attachment to identical cadherins present on adjacent cells. p120-catenin (p120) stabilizes cadherins to the cell surface and absence of p120 significantly reduces the presence cell surface cadherins. Previously, we showed that ablation of p120 in mice also results in malformed enamel that abrades from the teeth. Therefore, both MMP20 and cadherins are required for enamel formation. We will determine (AIM 1) how loss of MMP20 affects ameloblast cell-cell interaction. We hypothesize that MMP20 cleaves the extracellular domain of cadherins, which releases intracellular signaling molecules from the disrupted cadherin complex, such as β-catenin, that are essential for enamel formation. Importantly, our preliminary data demonstrate that MMP20 cleaves the extracellular domain of E-cadherin and we propose to test our hypothesis by use of a stably transfected ameloblast derived cell line (ameloblast-lineage cells, ALC) that can be induced to express high levels of activated MMP20. Normal enamel has a decussating (interlacing) rod pattern. Each rod is formed by one ameloblast and each rod preserves a complete record of the migratory path of the ameloblast that formed it. Mmp20 null mouse enamel has either a highly dysplastic rod pattern or no rod pattern at all. We will determine (AIM 2) if MMP20 enhances ameloblast movement. We hypothesize that MMP20 cleaves the extracellular domains of cadherins and that this is required for ameloblasts to move synchronously in rows to form the complex decussating enamel rod patterns. Intriguingly, it is at precisely the initiation of movement that the ameloblasts switch from expressing predominantly E-cadherin to predominantly N-cadherin. N-cadherin expression in epithelial cells promotes cell movement. This opens exciting possibilities wherein MMP20 may facilitate the cadherin switch and facilitate cell movement via cadherin hydrolysis. We will determine (AIM 3) if N-cadherin ablation in ameloblasts disrupts the normal decussating enamel rod pattern. We hypothesize that the E-, to N-cadherin switch is essential for ameloblast movement and, therefore, for establishing the decussating enamel rods. Our overall hypothesis is that the E- to N-cadherin switch allows ameloblasts to move laterally in rows to form the decussating enamel rod pattern and that MMP20 facilitates this process by releasing these extracellular cadherin contacts and associated intracellular signaling factors. Project Description Page 6

首席研究员/计划主任（最后，第一，中间）：巴特利特，约翰，D。该应用的目的是表征基质金属蛋白酶-20（MMP20）和N-的作用牙釉质发育过程中的木质细胞运动和细胞 - 细胞附着中的钙粘蛋白。 MMP20 对于牙釉质形成至关重要。缺乏功能性MMP20的人和老鼠出现了惊人的畸形牙釉质薄，柔软，很容易从底色的牙本质上擦拭。在MMP20无效的小鼠中秘密阶段的成熟木材不能正确进入发展的成熟阶段，一旦到达成熟的细胞重叠并互相长在彼此上。这表明成成布细胞细胞附着和 MMP20无效小鼠的信号传导改变。钙粘蛋白是跨细胞膜的蛋白质家族介导相邻细胞上存在的同一钙粘蛋白的附着。 P120-Catenin（P120）稳定钙粘蛋白到细胞表面和不存在p120可显着降低细胞表面钙粘蛋白。之前，我们表明，小鼠中P120的消融还会导致牙齿从牙齿上覆盖的畸形。因此，MMP20和钙粘蛋白都是搪瓷形成所必需的。我们将确定（目标1）如何损失 MMP20影响成熟的细胞细胞相互作用。我们假设MMP20裂解细胞外钙粘蛋白的结构域，该结构蛋白从破坏的钙粘蛋白络合物中释放细胞内信号分子，例如β-catenin，对于牙釉质形成至关重要。重要的是，我们的初步数据表明 MMP20切割E-钙粘蛋白的细胞外结构域，我们建议通过使用A来检验假设可诱导以表达的精美翻译成成木细胞系（ALC）高水平的激活MMP20。正常搪瓷具有横断性（交织）杆图案。每个杆形成通过一个木板细胞，每个杆保留了成成木的迁移路径的完整记录形成了。 MMP20零小鼠搪瓷具有高度异型的棒图案，或根本没有杆图案。我们将确定（AIM 2）MMP20是否增强了成成细胞运动。我们假设MMP20裂解钙粘蛋白的细胞外结构域，成熟细胞在行中同步移动至形成复杂的十分搪瓷杆图案。有趣的是，正是运动的倡议成纤维细胞从主要表达E-钙粘着蛋白转变为主要是N-钙粘着蛋白。上皮细胞中的表达促进细胞运动。这打开了MMP20的激动人心的可能性促进钙粘蛋白开关，并通过钙粘蛋白水解促进细胞运动。我们将确定（目标3）如果 N-钙粘蛋白在成成木中的消融会破坏正常的牙釉质棒图案。我们假设这一点 e-至n-钙粘蛋白开关对于成熟细胞运动至关重要，因此，建立十二杆的搪瓷杆。我们的总体假设是，E-至N-钙粘蛋白开关允许成成木横向移动行以形成十二线的搪瓷杆图案，MMP20通过释放这些细胞外钙粘蛋白接触和相关的细胞内信号传导因子。项目说明第6页

项目成果

期刊论文数量（30）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

DOI：
10.3389/fphys.2014.00240
发表时间：
2014
期刊：
Frontiers in physiology
影响因子：
4
作者：
Bartlett JD;Simmer JP
通讯作者：
Simmer JP

Why Does Enamel in Klk4-Null Mice Break above the Dentino-Enamel Junction?

DOI：
10.1159/000324260
发表时间：
2011-01-01
期刊：
CELLS TISSUES ORGANS
影响因子：
2.7
作者：
Simmer, James P.;Hu, Yuanyuan;Hu, Jan C. -C.
通讯作者：
Hu, Jan C. -C.

Transcription factor FoxO1 is essential for enamel biomineralization.

DOI：
10.1371/journal.pone.0030357
发表时间：
2012
期刊：
PloS one
影响因子：
3.7
作者：
Poché RA;Sharma R;Garcia MD;Wada AM;Nolte MJ;Udan RS;Paik JH;DePinho RA;Bartlett JD;Dickinson ME
通讯作者：
Dickinson ME

MMP20 and KLK4 activation and inactivation interactions in vitro.

DOI：
10.1016/j.archoralbio.2013.08.005
发表时间：
2013-11
期刊：
ARCHIVES OF ORAL BIOLOGY
影响因子：
3
作者：
Yamakoshi, Yasuo;Simmer, James P.;Bartlett, John D.;Karakida, Takeo;Oida, Shinichiro
通讯作者：
Oida, Shinichiro

Cleavage site specificity of MMP-20 for secretory-stage ameloblastin.