microRNA tuning of neural crest osteogenesis

项目总结 每4.5分钟，就有一个婴儿出生时就有先天缺陷，包括影响头面部骨骼的先天缺陷。 这些面部畸形会导致毁容，导致长期的心理影响，通常 与身体功能障碍相关，给受影响的个人和他们的 家人。尽管大多数严重的发育病理的原因尚不清楚，但很明显 神经脊(NC)细胞的不适当形成和分化，这些细胞通常会引起 受影响的头面部骨骼中的成骨细胞起着很大的作用。鉴于两者之间的因果关系 失控的NC成骨细胞分化及其引起的组织畸形 了解支持NC发展的分子网络对于潜在的治疗或 预防头面部缺陷，但还远远没有完成。例如，表观遗传调节器的贡献， 例如microRNAs(MiRNAs)对头面部骨骼形成的影响仍未被研究，尽管它们 有可能成为诊断标记物。 在这里，我们研究了通过我们拥有的特定miRNA miR361对NC发育的表观遗传调节 之前在我们实验室的NC成骨的体外模型中被确认为促成骨作用。刻画 MiR361在小鼠和非洲爪哇胚胎中的表达结构域与骨骼和 当miR361在这些生物中被敲除或过表达时，NC表型将验证miR361的功能 MiR361在体内NC发育过程中的作用。用AN评价MiR361的S对NC发展的贡献 创新有效的基于人多能干细胞的体外NC分化模型将展示 与这种微小RNA在人类发育中的相关性。阐述了miR361mRNA的直接靶点和 识别miR361下游转录调控的NC特定基因座将定义 这种miRNA在NC细胞中的转录激活与其随后的 成骨细胞分化。这一知识的影响力很大，因为目前公众还没有任何信息 结构域可以解释miR361在NC骨发育中的作用，也不能解释miR361在骨发育的任何方面 分化、发育或疾病。这项研究的结果将有助于开发一种 更全面地了解颅面部成骨，包括表观遗传调节因子和 有望阐明人类头面部发育障碍的原因和治疗方法， 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.