Defining BMP-responsive lncRNA for bone regeneration

描述（由申请人提供）：多能细胞具有分化成体内几乎任何细胞的能力，是再生医学和修复骨等缺陷组织的有力工具。然而，它们的临床应用仍然存在一些挑战，其中主要是它们形成肿瘤的倾向。在植入诱导多能细胞或胚胎干细胞后经常观察到自发性畸胎瘤形成。虽然已经描述了诸如通过FACS免疫耗竭SSEA-5+细胞、掺入响应更昔洛韦的自杀基因和使用小分子抑制剂的方法，但是没有一种被证明是完全成功的。最近的研究已经表明，表观遗传景观在细胞命运的规范中起着关键作用，并且了解这可能是如何调节的对于促进多能细胞在治疗策略中的安全和有效使用以替代缺陷组织如骨至关重要。新出现的数据描述了一类新的非编码RNA，范围从200个核苷酸到10多个核苷酸，在给定的细胞类型中大致与蛋白质编码mRNA一样多样。已经发现这些长的非编码RNA与组蛋白甲基化的小分子调节剂相互作用，靶向转录活性或基因沉默的特定结构域。非编码RNA被控制多久以及它们在调节分化中的确切作用仍然不确定，但随着更好的理解，存在重新定向多能细胞发育过程的潜力。这将是我们提案的重点。我们将评估诱导多能干细胞和胚胎干细胞如何对BMP-2做出反应，并定义全转录组反应和染色质景观的变化。整合两种细胞系的数据，我们将确定新的长非编码转录响应BMP-2。我们将期待操纵这些新的长非编码RNA转录本，并评估多能状态和骨分化潜力的变化。最后，我们还将评估多能细胞在操纵新型长非编码RNA后的体内反应。具体而言，将评价临界尺寸颅骨缺损模型中的骨再生能力和畸胎瘤形成潜力。我们希望这些创新研究的结果能够确定一种突破性的方法来理解和调节细胞命运的决定，从而开发出安全的基于细胞的多能细胞疗法。

DESCRIPTION (provided by applicant): With the ability to differentiate into almost any cell in the body, pluripotent cells represent a powerful tool for regenerative medicine and repair of deficient tissues such as bone. Several challenges to their clinical application remain, however, chief among which is their propensity to form tumors. Spontaneous teratoma formation has been frequently observed following implantation of induced pluripotent cells or embryonic stem cells. While approaches such as immunodepletion of SSEA-5+ cells by FACS, incorporation of suicide genes responsive to ganciclovir, and use of small molecular inhibitors have been described, none have proven completely successful. Recent studies have now shown the epigenetic landscape to play a key role in the specification of cell fate, and understanding how this may be regulated would be critial to facilitate safe and efficient use of pluripotent cells in therapeutic strategies to replace deficient tissues such as bone. Emerging data have described a novel class of noncoding RNAs ranging from 200 nucleotides to over 10 kilobases that are roughly as diverse in a given cell type as protein---coding mRNA. These long noncoding RNAs have been found to interact with small molecule regulators of histone methylation, targeting specific domain for transcriptional activity or gene silencing. How long noncoding RNAs are controlled and their precise role in regulating differentiation remains undefined, but with better understanding, the potential exists to redirect the developmental process in pluripotent cells. This will be the focus of our proposal. We will evaluate how induced pluripotent stem cells and embryonic stem cells respond to BMP-2 with definition of whole transcriptome response and changes to the chromatin landscape. Integrating data from both cell lines, we will then identify novel long noncoding transcripts responsive to BMP-2. We wil look to manipulate these novel long noncoding RNA transcripts and evaluate for changes to the pluripotent state and bone differentiation potential. Finally, we will also evaluae the in vivo response of pluripotent cells following manipulation of novel long noncoding RNAs. Specifically, the ability for both bone regeneration in a critical-sized calvaril defect model and the teratoma formation potential will be evaluated. We expect result of these innovative studies to identify a ground---breaking approach to understand and regulate cell fate determination, allowing for development of safe cell---based therapies employing pluripotent cells.