Phosphodiesterase Inhibitors Sildenafil and Vardenafil Reduce Zebrafish Rod Photoreceptor Outer Segment Shedding.
Phosphodiesterase Inhibitors Sildenafil and Vardenafil Reduce Zebrafish Rod Photoreceptor Outer Segment Shedding.
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DOI：
10.1167/iovs.17-21958
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发表时间：
2017-11-01
影响因子：
4.4
通讯作者：
Jensen AM
中科院分区：
文献类型：
--
作者：
Campbell LJ;Jensen AM
脊椎动物视杆细胞经历日常生长和脱落以更新视杆细胞外节（ROS），一种含有光转导机制的修饰的纤毛。它已被证明，活性氧的脱落是由光暗周期的调节，但是，我们还没有一个令人满意的理解的分子机制，这种调节的基础。鉴于光转导依赖于cGMP通过磷酸二酯酶6（PDE 6）的水解，我们研究了ROS的生长和脱落与cGMP特异性PDE抑制剂处理的斑马鱼。我们使用转基因斑马鱼，表达诱导型，跨膜结合的mCherry蛋白，形成一个条纹的ROS后，热休克脉冲，并作为一个标记的ROS更新。将斑马鱼在恒定黑暗中饲养或在热休克后用PDE抑制剂处理。在从处理的视网膜收集的共焦z堆叠中分析生长和脱落的测量。与黑暗饲养的斑马鱼一样，用PDE 5/6抑制剂西地那非和伐地那非处理的幼体和成体的散毒减少，但用PDE 5抑制剂他达拉非处理的幼体和成体的散毒没有减少。此外，伐地那非明显影响棒内段形态。西地那非对脱落的抑制作用在药物去除后可逆。最后，视锥细胞比视杆细胞对西地那非和伐地那非的毒性作用更敏感。我们发现，PDE 6的药理学抑制模仿长时间恒定黑暗对脱落的抑制。数据显示，光暗循环对ROS更新的影响部分地通过激活光转导机制启动脱落过程来调节。
The vertebrate rod photoreceptor undergoes daily growth and shedding to renew the rod outer segment (ROS), a modified cilium that contains the phototransduction machinery. It has been demonstrated that ROS shedding is regulated by the light–dark cycle; however, we do not yet have a satisfactory understanding of the molecular mechanisms that underlie this regulation. Given that phototransduction relies on the hydrolysis of cGMP via phosphodiesterase 6 (PDE6), we examined ROS growth and shedding in zebrafish treated with cGMP-specific PDE inhibitors. We used transgenic zebrafish that express an inducible, transmembrane-bound mCherry protein, which forms a stripe in the ROS following a heat shock pulse and serves as a marker of ROS renewal. Zebrafish were reared in constant darkness or treated with PDE inhibitors following heat shock. Measurements of growth and shedding were analyzed in confocal z-stacks collected from treated retinas. As in dark-reared zebrafish, shedding was reduced in larvae and adults treated with the PDE5/6 inhibitors sildenafil and vardenafil but not with the PDE5 inhibitor tadalafil. In addition, vardenafil noticeably affected rod inner segment morphology. The inhibitory effect of sildenafil on shedding was reversible with drug removal. Finally, cones were more sensitive than rods to the toxic effects of sildenafil and vardenafil. We show that pharmacologic inhibition of PDE6 mimics the inhibition of shedding by prolonged constant darkness. The data show that the influence of the light–dark cycle on ROS renewal is regulated, in part, by initiating the shedding process through activation of the phototransduction machinery.
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影响因子：
3.8
作者：
Burnside, B;Evans, M;Fletcher, R T;Chader, G J
通讯作者：
Chader, G J
影响因子：
4.3
作者：
Dooley, Christopher M.;Schwarz, Heinz;Geisler, Robert
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Geisler, Robert
影响因子：
3.5
作者：
D'Cruz, PM;Yasumura, D;Vollrath, D
通讯作者：
Vollrath, D
影响因子：
1.8
作者：
BOK, D;YOUNG, RW
通讯作者：
YOUNG, RW
影响因子：
4.4
作者：
Erickson T;Nicolson T
通讯作者：
Nicolson T