microRNA tuning of neural crest osteogenesis

项目摘要 每4分半钟，就有一个婴儿出生时有先天缺陷，包括影响颅面骨骼的缺陷。 这些面部畸形导致毁容，导致长期的心理影响， 与身体功能障碍有关，给受影响的个人及其 家庭虽然大多数这些严重发育病理的原因仍然未知，但很明显， 神经嵴（NC）细胞的不适当的形成和分化，这些细胞通常会引起 受影响的颅面骨骼中的成骨细胞，起着很大的作用。考虑到两者之间的因果关系 NC的成骨细胞分化受到错误控制，并由此产生组织畸形， 了解NC发展背后的分子网络对于潜在的治疗或 预防颅面缺损，但远未完成。例如，表观遗传调节因子的作用， 如microRNA（miRNAs），对颅面骨形成的影响仍未得到充分研究，尽管它们 作为诊断标志物的潜力。 我们在这里研究了一种特定的miRNA miR 361对NC发育的表观遗传调控， 先前在我们的实验室中被鉴定为在NC-骨生成的体外模型中是促骨生成的。表征 小鼠和非洲爪蟾胚胎中的miR 361表达结构域，以及骨骼和 当miR 361在这些生物体中被敲除或过表达时，NC表型将验证 miR 361在体内NC发育期间的表达。使用一种新的方法评估miR 361对NC发展的贡献 基于人类多能干细胞的创新和有效的体外NC分化模型将显示 与人类发育的关系。详细阐述了miR 361 mRNA的直接靶点， 鉴定在miR 361下游转录调节的NC特异性基因座将定义 这种miRNA与NC细胞中的转录激活及其随后的 成骨细胞分化这些知识具有很强的影响力，因为目前公众还没有任何信息。 结构域可以解释miR 361在NC骨发育中的作用，也可以解释miR 361在NC骨发育的任何方面的作用。 分化、发育或疾病。从这项研究中获得的结果将有助于发展一个 更全面地了解颅面骨生成，包括表观遗传调节因子， 有望阐明人类颅面区域发育障碍的原因和治疗， 这在NIDCR的长期计划中具有很高的优先级。

PROJECT SUMMARY Every 4 ½ minutes, a baby is born with a birth defect, including such that affect the craniofacial skeleton. These facial malformations cause disfigurement leading to long-term psychological impact and are often associated with physical dysfunction imposing tremendous burden on the affected individuals and their families. Although the causes for most of these severe developmental pathologies are still unknown, it is clear that the inappropriate formation and differentiation of neural crest (NC) cells, the cells that normally give rise to the osteoblasts in the affected craniofacial skeleton, plays a large part. Given the causality between miscontrolled osteoblast differentiation from the NC and the tissue malformations arising from it, an understanding of the molecular networks underlying NC development is crucial for the potential treatment or prevention of craniofacial defects, yet far from complete. For instance, the contribution of epigenetic regulators, such as microRNAs (miRNAs), to the formation of the craniofacial bones remains understudied, despite their potential as diagnostic markers. We study here the epigenetic regulation of NC development by a specific miRNA, miR361, which we have previously identified in our lab as being pro-osteogenic in an in vitro model of NC-osteogenesis. Characterizing the miR361 expression domain in mouse and Xenopus embryos coupled with the assessment of skeletal and NC phenotypes when miR361 is knocked out or overexpressed in these organisms will validate the function of miR361 during NC development in vivo. Assessing miR361's contribution to NC development using an innovative and effective in vitro NC differentiation model based on human pluripotent stem cells will show relevance for this microRNA in human development. Elaborating on the direct miR361 mRNA target and identifying NC-specific loci that are transcriptionally regulated downstream of miR361 will define the relationship between this miRNA, transcriptional activation in NC cells and their subsequent propensity for osteoblast differentiation. This knowledge is highly impactful as there is currently no information in the public domain that could explain the role of miR361 in bone development from the NC nor in any aspect of differentiation, development or disease. The results gained from this study will aid in the development of a more complete understanding of craniofacial osteogenesis that is inclusive of epigenetic regulators and promises to illuminate causes and treatments of developmental disorders of the craniofacial region in humans, which has a high priority in NIDCR's long-range plan.