In vivo analysis of mechanotransduction

机械转导的体内分析 生物管中的细胞必须整合生物化学和机械线索，以扩大或 以协调一致的方式。对不断变化的状态的不适当反应 心脏病、高血压和哮喘等疾病。尽管生物物理学的见解 从工程基质上的细胞生物学，许多重要问题仍然存在， 机械信息如何被细胞感知，转化为生化信号， 整合以产生协调的组织水平反应。例如，多细胞生物 收缩性在空间和时间上的调节如何诱导和繁殖的生化 由机械信号调节的信号组织内不同类型的细胞如何协调 他们的行动？为了解决这些问题，我们开发了一个体内模型，C。elegans 受精囊是线虫生殖系统中的管状组织，由24个 通过环形瓣膜连接到子宫的平滑肌样细胞。的主要优势 当卵母细胞进入时，细胞自然地伸展和收缩， 适合于定量活体成像和靶向遗传操作， 以及在完整组织中操作单个细胞。我们发现 卵母细胞进入诱导Ca 2+脉冲扫过整个组织，最终在一个协调的 将受精胚胎推入子宫的收缩。Ca 2+释放和收缩性 受精囊和瓣膜是协调的，使得当受精囊袋收缩时， 瓣膜扩张以允许受精胚胎离开。高度保守的基因网络调节着这些 过程，这表明我们的研究结果广泛适用于其他收缩系统。这里我们 提出遗传编码生物传感器、蛋白质组学、分子4D成像的组合 遗传学和建模，以阐明协调Ca 2+信号转导的机制， 对拉伸的反应。具体来说，我们将1）检验异源三聚体G蛋白， Gαs，通过PKA信号调节受精囊收缩; 2）通过以下机制模拟： 哪种伸展触发钙释放和信号传播;以及3）确定瓣膜如何 自主地和通过来自受精囊袋的通信来调节收缩性。 这项研究将导致我们对基本的理解的重要进展 细胞将机械信息转化为生化信号的机制，以及如何 这种信号传导被整合以调节组织功能。

In vivo analysis of mechanotransduction Cells in biological tubes must integrate biochemical and mechanical cues in order to expand or contract in a coordinated manner. Inappropriate responses to changing states underlie conditions such as heart disease, hypertension and asthma. Despite insights from biophysics and from cell biology on engineered substrates, many important questions remain regarding how mechanical information is sensed by cells, translated into biochemical signals, and integrated to produce a coordinated tissue-level response. For example, how is multicellular contractility regulated in space and time? How are the induction and propagation of biochemical signals regulated by mechanical cues? How do different cell types within a tissue coordinate their actions? To address these questions, we have developed an in vivo model, the C. elegans spermatheca, which is a tubular tissue in the nematode reproductive system comprised of 24 smooth-muscle-like cells that connect to the uterus via a toroidal valve. The major advantages of this system are that the cells are naturally stretched and contract as oocytes enter, and are amenable to quantitative live imaging and targeted genetic manipulation, enabling observation and manipulation of individual cells in the context of an intact tissue. We have discovered that oocyte entry induces Ca2+ pulses that sweep across the tissue, culminating in a coordinated contraction that pushes the fertilized embryo into the uterus. Ca2+ release and contractility in the spermatheca and valve are coordinated such that while the spermathecal bag contracts, the valve dilates to allow exit of the fertilized embryo. Well-conserved gene networks regulate these processes, suggesting broad applicability of our findings to other contractile systems. Here, we propose a combination of 4D imaging of genetically-encoded biosensors, proteomics, molecular genetics, and modeling to elucidate the mechanisms which coordinate Ca2+ signaling in response to stretch. Specifically, we will 1) test the hypothesis that the heterotrimeric G protein, Gαs, signals through PKA to regulate spermathecal contractility; 2) model the mechanisms by which stretch triggers calcium release and signal propagation; and 3) determine how valve contractility is regulated, both autonomously and via communication from the spermathecal bag. This research will lead to important advances in our understanding of the fundamental mechanisms by which cells convert mechanical information into biochemical signals, and how this signaling is integrated to regulate tissue function.