Sonogenetic Remote Control of Cellular Function

摘要 荧光蛋白和光遗传学的发现和发展使生物学发生了革命性的变化 可以用可见光对特定的细胞过程进行成像和控制。虽然这些工具已启用 不计其数的生物发现，光对活组织的穿透力很差，这使得使用光学 在完好的动物身上的技术。因此，从深部神经元的信号传递到生物现象- 大脑区域，到免疫细胞对肿瘤的渗透，到胃肠道的微生物定植，都是 在其自然的活体环境中进行研究具有挑战性。如果不是光，而是可以想象和 使用更具穿透性的能量形式(如超声波)操纵细胞功能，这将打开 以前无法触及的活体生物学领域来指导研究。此外，它还将加强 通过允许在给药后观察和控制细胞药物来开发基于细胞的治疗方法 进入人体。超声波的物理特性使其成为深部组织细胞通讯的理想方式。 在兆赫范围内的声波被组织弱散射，因此可以穿透几厘米进入 尸体。超声波的波长约为100微米，旅行时间为1毫秒，可以访问许多密钥 结构和流程。当被聚焦时，声波可以将机械和热能传递到精密 解剖位置。这些特性已经使超声波成为世界上应用最广泛的 医学成像和非侵入性外科技术。然而，超声波作为一种 用于细胞成像和控制的工具由于缺乏将其连接到 特定细胞和生物分子的功能。在之前的工作中，夏皮罗实验室率先使用了超声波 在细胞和分子成像中，通过开发第一个用于超声的声学报告基因和生物传感器， 目标是“像荧光蛋白在荧光显微镜中所做的那样，为超声波所做的事情”。主要目标是 我们提出的新的研究方向之一是通过给出 声波控制特定细胞功能的能力，如神经元兴奋、基因表达和 体内的细胞内信号传递。该方法的基本原理是：(1)利用聚焦超声沉积 组织中特定位置的声能，(2)使用遗传编码的“声学天线”将其转化为 能量转化为局部机械力，以及(3)利用该力驱动机械敏感感受器产生 特定的细胞信号。我们将在神经元和免疫细胞中实施这种方法，以实现独特的 神经科学和细胞治疗的应用。如果成功，这项工作将有助于建立新的领域 声遗传学为研究人员和临床医生提供了前所未有的“点击”细胞的能力 并告诉他们该怎么做。

SUMMARY The discovery and development of fluorescent proteins and optogenetics revolutionized biology by making it possible to image and control specific cellular processes with visible light. While these tools have enabled countless biological discoveries, the poor penetration of light into living tissue makes it difficult to use optical techniques in intact animals. As a result, biological phenomena ranging from the signaling of neurons in deep- brain regions, to the infiltration of immune cells into tumors, to the microbial colonization of the GI tract, are challenging to study within their natural in vivo context. If instead of light it were possible to visualize and manipulate cellular function using a more penetrant form of energy such as ultrasound, this would open previously inaccessible domains of in vivo biology to direct investigation. In addition, it would enhance the development of cell-based therapies by allowing cellular agents to be seen and controlled after administration into the human body. The physics of ultrasound make it an ideal modality for deep-tissue cellular communication. Sound waves in the MHz range are weakly scattered by tissue and can therefore penetrate several cm into the body. With wavelengths on the order of 100 µm and travel times < 1 ms, ultrasound can access many key structures and processes. When focused, sound waves can deliver mechanical and thermal energy to precise anatomical locations. These properties have already made ultrasound one of the world’s most widely used technologies for medical imaging and non-invasive surgery. However, the potential of ultrasound to serve as a tool for cellular imaging and control has been relatively untapped due to a lack of methods to connect it to the function of specific cells and biomolecules. In previous work, the Shapiro lab has pioneered the use of ultrasound in cellular and molecular imaging by developing the first acoustic reporter genes and biosensors for ultrasound, aiming to “do for ultrasound what fluorescent proteins have done for fluorescence microscopy”. The major goal of our proposed new research direction is to “do for ultrasound what optogenetics has done for light” by giving sound waves the ability to control specific cellular functions such as neuronal excitation, gene expression and intracellular signaling in vivo. The basic principle of our approach is to (1) use focused ultrasound to deposit acoustic energy at a specific location in tissue, (2) use genetically encoded “acoustic antennae” to convert this energy into local mechanical force, and (3) use this force to actuate mechanosensitive receptors to produce specific cellular signals. We will implement this approach in neurons and immune cells to enable unique neuroscience and cell therapy applications. If successful, this work will help establish the new field of sonogenetics by providing researchers and clinicians with the unprecedented ability to “point and click” on cells deep within the body and tell them what to do.