Chemical interrogation of metabolic tissue crosstalk

项目摘要。外周代谢组织参与广泛的器官间串扰，以维持 全身葡萄糖和脂质稳态。这种长距离的细胞间通讯是由血液介导的 分泌的多肽。在过去十年中，人们重新对确定其他 由代谢组织分泌的蛋白质。这是因为分泌蛋白的集合（例如，分泌蛋白组） 来自代谢细胞类型的多肽量很大，而且特征也很差，因此许多额外的多肽 介导周围组织串扰可能仍有待发现。不难想象， 这些孤儿因子中的许多代表了新的信号传导途径， 肥胖症、糖尿病和相关代谢紊乱的靶点。通常，解决这个问题的方法依赖于 试图预测而不是直接测量体内多肽分泌的替代方法 事件在最近的工作中，我们引入了一种体内化学方法， 策略：直接在活体动物中测量代谢组织分泌物组（Wei等，Nat.Chem.Biol.2020）。 重要的是，这种化学策略提供了独特的见解的组成和动态的分泌 在小鼠中，这是现有的体外或计算方法无法预测的。这项建议 旨在进一步发展这些化学方法，以生成完整的内分泌图 分泌的多肽介导外周代谢组织串扰。为了实现这一目标，我们将 (1)产生外周代谢组织多肽分泌组的6个器官、15个细胞类型图谱，并确定 这些分泌体如何被代谢紊乱如肥胖、饮食、环境 温度和身体活动;（2）开发新的体内化学物质，使高分辨率映射 通过蛋白水解切割事件产生的分泌多肽片段;和（3）整合代谢组织 通过体内化学脉冲追踪方法将分泌体引入内分泌回路。成功完成 这个高风险，高回报的项目将提供一个化学工具箱解剖细胞分泌，开放 组织串扰中潜在的重要新领域，并最终实现“捕获”的长期愿景 组织串扰的途径来对抗肥胖症、2型糖尿病和相关的代谢紊乱。

PROJECT SUMMARY. Peripheral metabolic tissues engage in pervasive inter-organ crosstalk to maintain systemic glucose and lipid homeostasis. This long-range intercellular communication is mediated by blood borne, secreted polypeptides. Over the last decade, there has been renewed interest in identifying additional proteins secreted from metabolic tissues. This is because the collection of secreted proteins (e.g., secretome) from metabolic cell types is large and also poorly characterized, and therefore many additional polypeptides that mediate peripheral tissue crosstalk likely remain to be discovered. It is not unreasonable to imagine that many of these orphan factors represent new signaling pathways and consequently potentially new therapeutic targets for obesity, diabetes, and related metabolic disorders. Typically, approaches to this problem have relied on surrogate methods that attempt to predict, rather than directly measure, in vivo polypeptide secretion events. In recent work, we have introduced an in vivo chemical methodology that enables a radically different strategy: to measure metabolic tissue secretomes directly in living animals (Wei et al., Nat. Chem. Biol. 2020). Importantly, this chemical strategy provides unique insights into the composition and dynamics of secretomes in mice that could not have been predicted by existing in vitro or computational approaches. This proposal seeks to further develop these chemical methodologies with the goal of generating a complete endocrine map of the secreted polypeptides that mediate peripheral metabolic tissue crosstalk. To achieve this goal, we will (1) produce a 6 organ, 15-cell type atlas of peripheral metabolic tissue polypeptide secretomes and determine how these secretomes are dynamically altered by metabolic perturbations such as obesity, diet, environmental temperature, and physical activity; (2) develop new in vivo chemistries that enable high-resolution mapping of secreted polypeptide fragments produced via proteolytic cleavage events; and (3) integrate metabolic tissue secretomes into endocrine circuits through in vivo chemical pulse-chase approaches. Successful completion of this high-risk, high-reward project will provide a chemical toolbox for dissecting cellular secretomes, open potentially important new areas in tissue crosstalk, and ultimately enable the long-term vision of “capturing” the pathways of tissue crosstalk to combat obesity, type 2 diabetes, and related metabolic disorders.