Ion Channel Drug Discovery Using Photoswitch Technology

描述（由申请人提供）：离子通道是允许带电分子选择性移动通过细胞膜的膜蛋白。许多疾病状态，如囊性纤维化、肌营养不良、高血压和心律失常是由离子通道病理引起的。离子通道已被药物发现界确定为治疗干预的优良靶标，但由于开发高质量、高通量功能性离子通道测定所涉及的技术障碍，“离子通道药物”的开发一直令人失望。Photoswitch Biosciences开发了一种技术，可以将小型纳米机器连接到离子通道上，从而通过光快速可逆地控制这些蛋白质。拟议项目的三个具体目标是：（1）优化哺乳动物细胞系中由光开关通道驱动的膜电位变化的动态范围，（2）优化细胞系、光开关通道和膜电位范围，以使用电生理检测来测定几种电压门控离子通道靶标，和（3）通过取代电生理学检测的指示剂染料将测定转换为全光学读出。第一个商业化的产品将是用于高通量离子通道药物发现的全光学离子通道测定和仪器。与现有技术相比，使用全光学技术进行离子通道测定具有几个优点：（1）消除了通道激活的液体添加，（2）对于高通量离子通道药物发现具有高度可扩展性，（3）每个数据点的价格至少比自动电生理学低100倍，（4）通道激活几乎比添加KCl快100倍。这种新的离子通道测定技术最重要的好处是能够快速可靠地控制膜电位。膜电位的这种控制允许开发可扩展的高通量状态依赖性测定，这在当前技术下是不可能的。这项突破性的技术将最终允许充分利用离子通道作为药物靶点。 公共卫生相关性：许多疾病都涉及称为离子通道的膜蛋白的功能问题。这些蛋白质负责神经系统，肌肉和几乎所有其他生理事件的正常运作。影响离子通道行为的药物已经被开发用于各种疾病，包括心脏问题，囊性纤维化和其他疾病。离子通道很难研究，因此很难找到针对离子通道的药物。Photoswitch Biosciences提出开发方法来增加研究离子通道的能力，从而增加离子通道药物的数量。

DESCRIPTION (provided by applicant): Ion channels are membrane proteins that allow the selective movement of charged molecules through cellular membranes. Many disease states, such as cystic fibrosis, muscular dystrophies, hypertension, and cardiac arrhythmias are caused by ion channel pathologies. Ion channels have been identified by the drug discovery community as excellent targets for therapeutic intervention but because of the technical hurdles involved in developing quality, high-throughput functional ion channel assays, the development of "ion channel drugs" has been disappointing. Photoswitch Biosciences has developed technology, which allows attaching small nanomachines to ion channels enabling rapid and reversible control of these proteins by light. The three Specific Aims of the proposed project are: (1) optimization of the dynamic range of changes in membrane potential driven by photoswitched channels in mammalian cell lines, (2) optimization of cell line, photoswitched channel and membrane potential range to assay several voltage-gated ion channel targets using electrophysiological detection, and (3) conversion of the assay to an all-optical readout by substituting indicator dyes for electrophysiology detection. The first commercial products to be developed will be all-optical ion channel assays and instruments for high- throughput ion channel drug discovery. The use of all-optical technology for ion channel assays has several advantages over existing techniques: (1) Elimination of liquid additions for channel activation, (2) Highly scalable for high-throughput ion channel drug discovery, (3) Price per datapoint is at least 100X less than automated electrophysiology, (4) Channel activation is almost 100X faster than KCl addition. The most important benefit of this new ion channel assay technology is the ability to rapidly and reliably control membrane potential. This control of membrane potential allows for the development of scalable high-throughput state-dependent assays, which is impossible with current technology. This breakthrough technology will finally allow the full exploitation of ion channels as drug targets. PUBLIC HEALTH RELEVANCE: Many diseases involve problems with the functioning of membrane proteins called ion channels. These proteins are responsible for proper operation of the nervous system, the muscles, and virtually all other physiological events. Drugs that affect ion channel behavior have been developed for a variety of diseases, including heart problems, cystic fibrosis, and other diseases. Ion channels are difficult to study and, because of this, drugs directed at ion channels have been difficult to find. Photoswitch Biosciences proposes to develop methods to increase the ability to study ion channels, and, thus, to increase the number of ion channel drugs.