Near-infrared optogenetic control of the human heart

项目概要/摘要： 心脏光遗传学是一项新兴技术，对心脏病的治疗具有重要的前景。 光遗传致动器是可以通过光调节的离子通道或泵，从而允许控制光遗传。 具有高空间和时间精度的细胞电活动。光遗传学不仅可以用于 阐明心脏细胞和心脏组织的电和机械功能，但潜在地恢复或 修复故障起搏器和传导组织。与电植入式起搏器不同，光遗传学 致动器可以允许对心脏起搏器和传导细胞的电活动进行光学调制。因此，在本发明中， 该技术具有未开发的治疗应用潜力。必须克服重大障碍 才能将这项技术应用于人类患者。大多数光遗传学致动器在细胞中操作。 450-600 nm范围的光，并且这些波长的光被心脏组织强烈散射并被心脏组织吸收。 血红蛋白。这些效应严重限制了目前可用的光遗传学致动器可以在其处的组织深度。 因此，它们的体内使用仅限于小型啮齿动物。为了克服这一障碍，使用较长的- 波长视蛋白最近被建议用于光遗传学。最新的红移视蛋白可以在 比常规的蓝色敏感通道视紫红质具有显著更大的组织深度。然而，即使是最 红移的视蛋白与血红蛋白的吸收光谱具有显著的重叠。因此，一种方法 这可以将致动器的操作范围扩展到近红外（> 700 nm;即，超出 血红蛋白吸收窗口）将是一个重大进步。这个项目的目标是共同表达 光遗传学执行器与新发现的酶，Cyp 27 c1，可以扩展现有的光谱范围， 将光遗传学致动器红移到近红外，从而允许光遗传学应用于 人类的心脏Cyp 27 c1被鱼类和两栖动物用来将它们的视觉扩展到黑暗中的近红外线。 淡水环境。这种酶通过增加一个额外的共轭双键来介导这种红移 视觉发色团11-顺式视网膜。Corbo实验室已经证明Cyp 27 c1可以类似地作用于 全反式视黄醛，光遗传致动器的发色团，以产生3，4-二脱氢视黄醛。而且有 最近的研究表明，在光遗传学致动器中用3，4-二脱氢视黄醇体外取代视黄醇， 使致动器的动作谱红移，强调了开发用于心脏的体内策略的价值。 应用.

Project Summary/Abstract: Cardiac optogenetics is an emerging technology with significant promise for the treatment of heart disease. Optogenetic actuators are ion channels or pumps that can be regulated by light, thus permitting the control of cellular electrical activity with high spatial and temporal precision. Optogenetics can be used not only to elucidate the electrical and mechanical functions of cardiac cells and heart tissue, but to potentially restore or repair malfunctioning pacemaker and conduction tissue. Unlike electrical implantable pacemakers, optogenetic actuators may permit optical modulation of electrical activity of cardiac pacemaker and conduction cells. Thus, this technology holds untapped potential for therapeutic applications. Significant hurdles must be overcome before this technology can be applied to human patients. The majority of optogenetic actuators operate in the 450-600 nm range, and light at these wavelengths is strongly scattered by cardiac tissue and absorbed by hemoglobin. These effects severely limit the tissue depth at which currently available optogenetic actuators can be used, thereby restricting their in vivo use to small rodents. To overcome this barrier, the use of longer- wavelength opsins has recently been suggested for optogenetics. The newest red-shifted opsins can operate at considerably greater tissue depths than conventional blue-sensitive channel-rhodopsins. Yet, even the most red-shifted opsins have significant overlap with the absorption spectrum of hemoglobin. Thus, an approach that could extend the operative range of actuators into the near-infrared (> 700 nm; i.e., beyond the hemoglobin absorption window) would be a major advance. The goal of this project is to co-express optogenetic actuators with a newly discovered enzyme, Cyp27c1, that can extend the spectral range of existing red-shifted optogenetic actuators into the near-infrared, thereby permitting optogenetic applications in the human heart. Cyp27c1 is used by fish and amphibians to extend their vision into the near-infrared in murky freshwater environments. The enzyme mediates this red-shift by adding an additional conjugated double bond to the visual chromophore, 11-cis retinal. The Corbo lab has demonstrated that Cyp27c1 can similarly act upon all-trans retinal, the chromophore of optogenetic actuators, to produce 3,4-didehydroretinal. Furthermore, a recent study showed that in vitro substitution of retinal with 3,4-didehydroretinal in optogenetic actuators can red-shift the actuator's action spectrum, underscoring the value of developing an in vivo strategy for cardiac applications.