Role of endosomal sorting in the biogenesis of extracellular vesicles

在发育和成人组织中，动态平衡细胞将内在和外在的信号整合成信号，与周围的细胞群体共享。这些信号可以同步或去同步细胞的行为，并协调单个细胞的位置和命运。形态成因梯度因其在图案形成中的作用而被深入研究。长期以来，这些梯度的分子形式被认为是分泌型蛋白配体，激活了受体细胞上不同的信号通路。这些信号通路的异常激活会导致癌症的进展。然而，越来越多的证据表明，细胞外小泡(EV)是这种信息的载体。它们是在体外和体内释放到细胞外空间的膜颗粒的异质性群体。但这些结构是如何从内体隔间释放出来的，以及如何从一个细胞向另一个细胞发出信号，仍然是个谜。在拟议的项目中，我们将在肿瘤细胞迁移的背景下研究EVS的分泌和信号转导。我们将重点研究电动汽车的来源以及是什么细胞过程调节了它们的释放。这将通过分析：(1)微囊和外体释放的动力学，(2)分泌型MVB的组成和调节，(3)多颜色STED的外体亚群，以及(4)细胞迁移中EV分泌的极化机制。具体地说，我们希望通过使用诱导的Wnt5A分泌来了解影响和调节EV分泌的内体分选事件，作为EV货物分类到sMVB中并以ESCRT-0依赖的方式释放的EV货物，以推断EV信号是如何在细胞定向迁移的背景下解码的。总而言之，该项目将提供对通过电动汽车进行蜂窝通信的深入了解。了解它们在迁移中的生物学作用将为细胞外信号通路增加一个新的层次。在拟议的项目中，我们将在肿瘤细胞迁移的背景下研究EVS的分泌和信号传递。我们将使用单细胞分析来机械地剖析EV释放的时空模式。具体地说，我们想要了解影响和调节其分泌的内体分选事件，并调查EV亚群的动态和生物发生。我们将专注于EV信号的组成，它们激活哪些通路，并推断EV信号是如何在细胞定向迁移的背景下被解码的。总而言之，该项目将提供对通过电动汽车进行蜂窝通信的深入了解。了解它们在迁移中的生物学作用，它们的传输和接收将为细胞外信号通路增加一个新的层面。

During development and adult tissue homeostasis cells integrate intrinsic and extrinsic cues into signals that are shared with the surrounding cell population. These signals can synchronize or desynchronize cellular behavior and coordinate position and fate of individual cells. Morphogens gradients have been intensively investigated for their role in pattern formation. The molecular form of these gradients was long considered to be secreted protein ligands, which activate different signaling pathways on receiving cells. Abberant activation of these signaling pathways leads to the progression of cancer. However, increasing evidence suggests that extracellular vesicles (EVs) are the carriers of such messages. They are a heterogeneous population of membrane particles released into the extracellular space in vitro and in vivo. But how these structures are released from endosomal compartments and how signaling from one cell to another occurs remains elusive. In the proposed project we will study the secretion and signaling of EVs in the context of cell migration in tumor cells. We will focus on the source of EVs and what cellular processes regulated their release. This will be done by analyzing: (1) the dynamics of microvesicles and exosomes release, (2) the composition and regulation of secretory MVBs, (3) exosomal subpopulations by multi-color STED and (4) the mechanism of polarized EVs secretion in cell migration.Specifically, we want to understand endosomal sorting events that influence and regulate EV secretion by using an induced Wnt5A secretion as a model EV cargo sorted into sMVBs and released in an ESCRT-0-dependent manner to deduce how EV signals are decoded in the context of directed cell migration. Altogether, this project will provide a deep insight into cellular communication via EVs. Understanding their biological role in migration will add a new layer to extracellular signaling pathways.In the proposed project we will study the secretion and signaling of EVs in the context of cell migration in tumor cells. We will use single cell assays to mechanistically dissect the spatio-temporal modalities of EV release. Specifically, we want to understand endosomal sorting events that influence and regulate their secretion and investigate the dynamics and biogenesis of subpopulations of EVs. We will focus on the composition of signaling EVs, which pathways they activate and deduce how EV signals are decoded in the context of directed cell migration. Altogether, this project will provide a deep insight into cellular communication via EVs. Understanding their biological role in migration, their transmission and reception will add a new layer to extracellular signaling pathways.