DEVELOPMENT OF PALATE AND CRANIOFACIAL MESENCHYME

腭和颅面间充质的发育

• 批准号: 2132277
• 负责人: ELIZABETH D HAY
• 金额: $ 21.52万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2132277
• 关键词: Retroviridae; antibody; antisense nucleic acid; cell differentiation; cell transformation; chick embryo; cleft palate; connective tissue development; embryo /fetus tissue /cell culture; embryogenesis; epithelium; face; head; histogenesis; immunocytochemistry; in situ hybridization; laboratory mouse; laboratory rat; mesenchyme; neural crest; oligonucleotides; osteocytes; palate; transforming growth factors; transmission electron microscopy

This grant proposal is about the development of the palate, with special attention to the role of the medial edge epithelium (MEE) and cranial neural crest mesenchyme. Mesenchymal cells arise by epithelial-mesenchymal transformation (BMT). They have the ability to invade collagen gels and other extracellular matrix (ECM), whereas epithelia sit on top of ECM and exhibit apical-basal polarity. Mesenchymal cells migrate through the matrix with front end/back end polarity. They differentiate into the cells that inhabit the ECM interior: fibroblasts, bone, melanocytes, and neurones. We will consider the following aspects of the origin and differentiation of the craniofacial mesenchymes that contribute to palatal morphogenesis. I. Mesenchymal Cell Lineages in the Developing Palate. Using recombinant retroviruses to label specific groups of cells in the embryo, we expect to confirm and extend our earlier study that MEE-derived mesenchyme forms fibroblasts but not bone, and to prove for the first time that head neural crest in the rodent consists of two physically separate cell populations, one of which forms connective tissue and the other, melanocytes and neurones. The significance of this study to students of palate morphogenesis is that it establishes a multiple origin of palate mesenchyme and calls attention to the fact that palate MEE does not die as previous authors thought. It casts a new light on roles the MEE might play in cleft palate. II. Effect of Bone Inducing Molecules on the Differentiation of Mesenchymal Cell Lineages. We will attempt to drive the cells above that do not normally form cartilage/bone to do so by administering BMP to them in vitro. It will be particularly interesting to see if mesenchyme formed from palate epithelium and neurogenic crest cells will undergo chondrogenesis under the influence of this powerful inducing agent. The results could have important impact on our ideas about the ability of "determined" cells (e.g., neurogenic crest) to reawaken apparently closed pathways of differentiation. III. Induction and Inhibition of Epithelial Fusion and EMT in Nonfusing and Fusing Palates. Chicken palates do not normally fuse probably because the MEE stratifies and periderm does not slough to expose the basal epithelia to each other. We will surgically remove the periderm and place chicken palatal shelves in close contact to try to induce formation of a midline seam. TGFbeta3 will be added to promote EMT from this seam and the fate of mesenchymal cells followed. Antibodies and antisense oligonucleotides to TGFbeta1-3 will be added to try to inhibit EMT from MEE of fused rodent palates. The recognition our recent work has given to the fact that MEE transforms to mesenchyme establishes a whole new way of looking at the possible role of TGFbeta's and sloughing of the outer layer of the MEE in palatogenesis. The immediate health relevance is to understanding normal development, but the work could give new insights into causes of congenital anomalies, especially cleft palate.

这项拨款提案是关于味觉的发展，特别是 注意内侧边缘上皮 (MEE) 和颅骨的作用 神经嵴间充质。间充质细胞由上皮间质细胞产生 转化（BMT）。它们有能力侵入胶原蛋白凝胶并 其他细胞外基质 (ECM)，而上皮位于 ECM 之上 表现出顶端-基底极性。间充质细胞通过 具有前端/后端极性的矩阵。它们分化成细胞 居住在 ECM 内部的细胞：成纤维细胞、骨、黑素细胞和 神经元。我们将考虑以下几个方面的起源和 颅面间质的分化有助于腭 形态发生。 I. 腭发育中的间充质细胞谱系。使用重组 逆转录病毒来标记胚胎中的特定细胞群，我们希望 证实并扩展了我们早期的研究，即 MEE 衍生的间充质形成 成纤维细胞而非骨骼，并首次证明头部神经 啮齿动物的嵴由两个物理上独立的细胞群组成， 其中一种形成结缔组织，另一种形成黑素细胞和 神经元。这项研究对味觉学生的意义 形态发生是它建立了上颚的多个起源 间充质并提醒人们注意上颚 MEE 不会像 以前的作者认为。它为 MEE 可能发挥的作用提供了新的视角 在腭裂中。 二.骨诱导分子对骨分化的影响 间充质细胞谱系。我们将尝试驱动高于该值的单元格 通常不会通过给予 BMP 来形成软骨/骨骼 体外。观察间充质是否形成将会特别有趣 来自腭上皮和神经源性嵴细胞的 在这种强大的诱导剂的影响下软骨形成。这 结果可能会对我们关于能力的看法产生重要影响 “确定的”细胞（例如，神经源性嵴）重新唤醒明显关闭的细胞 分化途径。 三．非融合中上皮融合和 EMT 的诱导和抑制 和融合味觉。鸡的上颚通常不会融合，可能是因为 MEE 分层，周皮不会脱落而暴露基底层 上皮细胞彼此相连。我们将通过手术切除周皮并放置 鸡腭架紧密接触，试图诱导形成 中线接缝。将添加 TGFbeta3 以促进从该接缝开始的 EMT 间充质细胞的命运随之而来。抗体和反义 将添加 TGFbeta1-3 寡核苷酸以尝试抑制 EMT 啮齿类动物上颚融合的 MEE。我们最近的工作给予的认可 MEE 转化为间充质的事实建立了一种全新的方式 研究 TGFbeta 和外层脱落的可能作用 MEE 在腭发育中的作用。 与健康直接相关的是了解正常发育，但是 这项工作可以为先天异常的原因提供新的见解， 尤其是腭裂。