Notch/Robo Regulated Mechanisms Governing Cell Fate Acquisition

项目负责人/主要研究者（Hinck，林赛，E.）： 在理解组织特异性干/祖细胞的作用及其能力方面存在根本性的差距 分裂和更新的。在乳腺等组织中，这些细胞经历扩张性生长， 每一次怀孕的区别然而，调控双核产奶细胞生成的机制 对肺泡细胞的了解很少。在这一知识差距被弥合之前，我们将无法支持 大量妇女产奶不足。这项研究的长期目标是 了解哺乳动物如何利用干/祖细胞来建立牛奶供应。最近，人们发现 大部分细胞在乳腺泡形成过程中变成多倍体， 生产本研究的目的是确定调节多倍体产生的信号通路 细胞通过内复制响应复制应激产生的DNA损伤，并确定 这些途径对牛奶生产的影响。中心假设是ROBO调节的NOTCH信号传导 调控DNA损伤分化反应和细胞内复制， 祖细胞扩增和分化。我们的假设是基于我们自己的初步数据， 差异调节肺泡发生和Notch信号，并且Robo/Notch信号共同调节 对DNA损伤的反应，我们发现这发生在肺泡形成过程中。这背后的理由是， 建议是，这些途径的识别将允许药物或饮食干预， 促进肺泡发育和产奶。在强有力的初步数据的指导下，三个假设将 1）ROBO 1通过限制一个或多个NOTCH的激活来促进分化 AVPs中的受体。2)ROBO 2通过激活一种或多种Notch受体的信号传导来抑制分化 或者直接地或者通过ROBO 1动作。3)复制压力，发生在扩张阶段， 妊娠是DNA损伤的来源，引发DNA损伤分化反应， 这是由Robo/Notch信号控制的。这项研究意义重大，因为它将 确定增加牛奶产量的新方法。这项研究是创新的，因为我们建议 利用干/祖细胞可以提高产奶量。以前的研究集中在 催乳素途径，并且仅产生具有显著负面副作用的药物。拟议的研究将 对产奶量不足的妇女及其无法受益的儿童产生积极影响 这种“液体黄金”。 PHS 398（修订版01/18批准至03/31/2020）

Program Director/Principal Investigator (Hinck, Lindsay, E.): There is a fundamental gap in understanding the role of tissue specific stem/progenitor cells and their capacity for division and renewal. In tissues such as the breast, these cells undergo expansive growth and differentiation with every pregnancy. Yet, mechanisms regulating the generation of binucleated, milk-producing alveolar cells are scarcely understood. Until this knowledge gap is closed, we will be unable to support the substantial number of women who produce insufficient milk. The long-term goal of this research is to understand how mammals harness stem/progenitor cells to build a milk supply. Recently, it was discovered that a large fraction of cells become polyploid during mammary alveologenesis, a process required for milk production. This proposal's objective is to identify the signaling pathways regulating the generation of polyploid cells via endoreplication in response to DNA damage generated by replication stress, and determine the impact of these pathways on milk production. The central hypothesis is that ROBO-regulated NOTCH signaling governs the DNA damage differentiation response and endoreplication that occurs in response to alveolar progenitor cell expansion and differentiation. Our hypothesis is based on our own preliminary data that ROBOs differentially regulate alveologenesis and Notch signaling, and that, together, Robo/Notch signaling regulates the response to DNA damage, which we find occurring during alveologenesis. The rationale underlying this proposal is that the identification of these pathways will allow for interventions, pharmacological or dietary, that improve alveolar development and milk production. Guided by strong preliminary data, three hypotheses will be tested in three Aims: 1) ROBO1 promotes differentiation by restricting the activation of one or more NOTCH receptors in AVPs. 2) ROBO2 inhibits differentiation by activating the signaling of one or more Notch receptors either directly or by acting through ROBO1. 3) Replication stress, occurring during the expansion phase of pregnancy, is the source of DNA damage, triggering the DNA damage differentiation response and endoreplication that is governed by Robo/Notch signaling. The proposed research is significant because it will identify new methods for increasing milk production. The proposed research is innovative because we propose that harnessing stem/progenitor cells can enhance milk production. Previous studies have focused on the prolactin pathway and only yielded drugs with significant negative side effects. The proposed research will have a positive impact for women who produce insufficient milk and their children who do not reap the benefits of this “liquid gold”. PHS 398 (Rev. 01/18 Approved Through 03/31/2020) Page Continuation Format Page