Unipotency of Tbx5+ embryonic cardiac progenitor cells to cardiomyocytes.

Tbx5 胚胎心脏祖细胞对心肌细胞的单能性。

• 批准号: MR/J007625/1
• 负责人: Kenta Yashiro
• 金额: $ 41万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FJ007625%2F1
• 关键词: Unipotency; Tbx5+; embryonic; cardiac; progenitor

Heart failure is a major cause of death in industrialized countries. Although the present medicines can attenuate the symptoms to some extent, the expected outcome is still poor. Therefore a new treatment is needed as soon as possible. Since heart failure is caused by the loss or poor functioning of heart muscle cells, destroyed or damaged during a heart attack, regeneration therapy seems promising by the replenishment of the damaged heart muscle with new heart muscle cells or heart muscle stem cells (cardiac progenitor cells; CPCs) created in the laboratory. However our current knowledge is too limited to be able to create sufficiently safe and effective cells for clinical use. Thus a much better understanding of CPCs is critical to bring such regeneration therapy into the clinical arena.It is known that CPCs are composed of two different populations known as the first and the second heart field. The first and the second heart fields are the origin of left side and the right side of the heart, respectively. A factor called Tbx5 is present in the first heart field and another two factors called Nkx2-5 and Isl1 are present in both the first and the second heart fields. CPCs positive for Nkx2-5 or Isl1 are known to give rise to heart muscle cells as well as other components of the heart. On the other hand, although CPCs positive for Tbx5, the first heart field, are known to produce heart muscle cells, whether the first heart field can also produce other cell types present in the heart is still largely unknown.To better understand CPCs, we have been studying CPCs from the earliest stage during embryogenesis with a state-of-art technique, single cell cDNA analysis. This technique allows us to study each a single CPC one by one, which brings detailed information with a resolution that other methods have never been able to provide. According to our data, we found the novel evidence that the first heart field CPCs are initially positive only for Tbx5, then become triple positive for Nkx2-5, Tbx5 and Isl1, and subsequently become double positive for Nkx2-5 and Tbx5. To confirm conclusively this sequential change of the first heart field CPCs according to the temporal order, we initially tried to trace Tbx5-expressing CPCs in the mouse embryonic heart by deliberately labeling Tbx5-expressing CPCs permanently with a fluorescent protein, eYFP. From this pilot study, we assume that the first heart field of Tbx5-expressing CPCs produces only heart muscle cells, which is quite different from Nkx2-5-expressing or Isl1-expressing CPCs.In this project, we will confirm whether our original assumption that Tbx5-expressing CPCs produce only heart muscle cells is true or not. We will trace Tbx5-expressing CPCs in detail with permanent eYFP label. This will enable us to consolidate the evidence of the sequential change of Tbx5-expressing CPCs as well as to clearly identify what type of the cells Tbx5-expressing CPCs give rise to. Furthermore, we aim to establish a new method to study Tbx5-expressing cardiac progenitor cells derived from mouse embryonic stem cells. Using this new method, we can further study Tbx5-expressing CPCs in vitro without using of animals, and we can test the use of Tbx5-expressing CPCs for the treatment of animal models of heart failure by the efficient enrichment of Tbx5-expressing CPCs. Thus, successful completion of this project will clearly demonstrate whether Tbx5-expressing CPCs can only provide heart muscle cells. Such novel knowledge in basic science as well as the establishment of a useful new tool for basic science study will greatly improve our understanding of heart muscle development. We strongly believe that completion of this project is one of the many steps towards the overall goal of the establishment of future regeneration therapies for heart failure.

心力衰竭是工业化国家的一个主要死亡原因。虽然目前的药物可以在一定程度上减轻症状，但预期的结果仍然很差。因此，需要尽快找到新的治疗方法。由于心力衰竭是由心肌细胞的丢失或功能不良引起的，在心脏病发作期间被破坏或损坏，再生疗法似乎很有希望通过在实验室中创造新的心肌细胞或心肌干细胞（心脏祖细胞；cpc）来补充受损的心肌。然而，我们目前的知识太有限，无法创造出足够安全有效的细胞用于临床。因此，更好地了解cpc对于将这种再生疗法引入临床领域至关重要。众所周知，心脏中心细胞由两个不同的群体组成，即第一和第二心脏区。第一心田和第二心田分别是心脏左侧和右侧的原点。一个叫做Tbx5的因子存在于第一心脏区，另外两个叫做Nkx2-5和Isl1的因子同时存在于第一和第二心脏区。已知Nkx2-5或Isl1阳性的cpc会产生心肌细胞以及心脏的其他成分。另一方面，虽然已知第一心野Tbx5阳性的CPCs产生心肌细胞，但第一心野是否也能产生心脏中存在的其他类型的细胞仍然很大程度上未知。为了更好地了解CPCs，我们一直在用最先进的技术——单细胞cDNA分析——从胚胎发生的最早阶段研究CPCs。该技术允许我们逐一研究单个CPC，从而提供其他方法无法提供的详细信息。根据我们的数据，我们发现了新的证据，第一心脏区CPCs最初仅对Tbx5呈阳性，然后对Nkx2-5、Tbx5和Isl1呈三阳性，随后对Nkx2-5和Tbx5呈双阳性。为了最终证实第一心野CPCs根据时间顺序的顺序变化，我们最初试图通过用荧光蛋白eYFP永久标记表达tbx5的CPCs来追踪小鼠胚胎心脏中表达tbx5的CPCs。从本初步研究中，我们假设表达tbx5的CPCs的第一个心脏野只产生心肌细胞，这与表达nkx2 -5或表达isl1的CPCs有很大的不同。在这个项目中，我们将证实我们最初的假设tbx5表达的cpc只产生心肌细胞是正确的还是错误的。我们将用永久eYFP标签详细追踪表达tbx5的cpc。这将使我们能够巩固表达tbx5的cpc序列变化的证据，并清楚地确定表达tbx5的cpc产生了什么类型的细胞。此外，我们旨在建立一种新的方法来研究来自小鼠胚胎干细胞的表达tbx5的心脏祖细胞。利用这种新方法，我们可以在体外进一步研究表达tbx5的CPCs，而无需使用动物，我们可以通过高效富集表达tbx5的CPCs来测试表达tbx5的CPCs对心力衰竭动物模型的治疗作用。因此，本项目的成功完成将清楚地证明表达tbx5的cpc是否只能提供心肌细胞。这些基础科学的新知识以及基础科学研究的新工具的建立将大大提高我们对心肌发育的认识。我们坚信，这个项目的完成是朝着建立未来心力衰竭再生疗法的总体目标迈出的众多步骤之一。

项目成果

GFRA2 Identifies Cardiac Progenitors and Mediates Cardiomyocyte Differentiation in a RET-Independent Signaling Pathway.

• DOI: 10.1016/j.celrep.2016.06.050
• 发表时间: 2016-07-26
• 期刊: Cell reports
• 影响因子: 8.8
• 作者: Ishida H;Saba R;Kokkinopoulos I;Hashimoto M;Yamaguchi O;Nowotschin S;Shiraishi M;Ruchaya P;Miller D;Harmer S;Poliandri A;Kogaki S;Sakata Y;Dunkel L;Tinker A;Hadjantonakis AK;Sawa Y;Sasaki H;Ozono K;Suzuki K;Yashiro K
• 通讯作者: Yashiro K

Retinoic acid signaling regulates sonic hedgehog and bone morphogenetic protein signalings during genital tubercle development.

• DOI: 10.1002/bdrb.20344
• 发表时间: 2012-02
• 期刊: Birth defects research. Part B, Developmental and reproductive toxicology
• 作者: Liu L;Suzuki K;Nakagata N;Mihara K;Matsumaru D;Ogino Y;Yashiro K;Hamada H;Liu Z;Evans SM;Mendelsohn C;Yamada G
• 通讯作者: Yamada G