Near-infrared optogenetic control of the human heart

项目摘要/摘要： 心脏光遗传学是一项新兴技术，在心脏病的治疗方面具有重要的前景。 光生致动器是可由光调节的离子通道或泵，从而允许控制 细胞电活动具有很高的空间和时间精度。光遗传学不仅可以用来 阐明心脏细胞和心脏组织的电和机械功能，但有可能恢复或 修复发生故障的起搏器和传导组织。与电动植入式起搏器不同，光生技术 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， 这项技术具有尚未开发的治疗应用潜力。必须克服重大障碍 在这项技术可以应用于人类患者之前。大多数光生致动器运行在 450-600 nm范围内，这些波长的光被心脏组织强烈散射并被 血红蛋白。这些效应严重限制了目前可用的光遗传致动器可以达到的组织深度 可以使用，从而将其在体内的使用限制在小型啮齿动物身上。为了克服这一障碍，使用更长的- 波长光学蛋白最近被建议用于光遗传学。最新的红移光学系统可以在 比传统的蓝色敏感通道-视紫红质-组织深度要大得多。然而，即使是最 红移视黄素与血红蛋白的吸收光谱有明显的重叠。因此，一种方法 这可能会将致动器的工作范围扩展到近红外(即，超出 血红蛋白吸收窗口)将是一项重大进展。这个项目的目标是共同表达 带有新发现的酶Cyp27c1的光遗传致动器，可以扩展现有的光谱范围 红移光生致动器进入近红外，从而允许光生应用于 人类的心脏。Cyp27c1被鱼和两栖动物用来在黑暗中将它们的视觉延伸到近红外 淡水环境。该酶通过增加一个额外的共轭双键来调节这种红移 对于视觉发色团，11顺式视网膜。Corbo实验室已经证明，Cyp27c1可以类似地作用于 全反式视网膜，光发生致动器的发色团，产生3，4-二脱氢视网膜。此外，a 最近的研究表明，在体外用3，4-二脱氢视网膜替代光遗传致动器中的视网膜可以 红移执行器的动作谱，强调开发心脏活体策略的价值 申请。

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.