PDF(Pubmed)
Abstract：
UNASSIGNED: Mechanical sensitive channels expressed in mammalian retinas are effectors of elevated pressure stresses, but it is unclear how their activation affects visual function in pressure-related retinal disorders.
UNASSIGNED: This study investigated the role of the transient potential channel vanilloid TRPV4 in photoreceptors and rod bipolar cells (RBCs) with immunohistochemistry, confocal microscopy, electroretinography (ERG), and patch-clamp techniques.
UNASSIGNED: TRPV4 immunoreactivity (IR) was found in the outer segments of photoreceptors, dendrites and somas of PKCα-positive RBCs and other BCs, plexiform layers, and retinal ganglion cells (RGCs) in wild-type mice. TRPV4-IR was largely diminished in the retinas of homozygous TRPV4 transgenic mice. Genetically suppressing TRPV4 expression moderately but significantly enhanced the amplitude of ERG a- and b-waves evoked by scotopic and mesopic lights (0.55 to 200 Rh*rod-1 s-1) and photopic lights (105-106 Rh*rod-1 s-1) compared to wild-type mice in fully dark-adapted conditions. The implicit time evoked by dim lights (0.55 to 200 Rh*rod-1 s-1) was significantly decreased for b-waves and elongated for a-waves in the transgenic mice. ERG b-wave evoked by dim lights is primarily mediated by RBCs, and under voltage-clamp conditions, the latency of the light-evoked cation current in RBCs of the transgenic mice was significantly shorter compared to wild-type mice. About 10% of the transgenic mice had one eye undeveloped, and the percentage was significantly higher than in wild-type mice.
UNASSIGNED: The data indicates that TRPV4 involves ocular development and is expressed and active in outer retinal neurons, and interventions of TRPV4 can variably affect visual signals in rods, cones, RBCs, and cone ON BCs.
UNASSIGNED: This study investigated the role of the transient potential channel vanilloid TRPV4 in photoreceptors and rod bipolar cells (RBCs) with immunohistochemistry, confocal microscopy, electroretinography (ERG), and patch-clamp techniques.
UNASSIGNED: TRPV4 immunoreactivity (IR) was found in the outer segments of photoreceptors, dendrites and somas of PKCα-positive RBCs and other BCs, plexiform layers, and retinal ganglion cells (RGCs) in wild-type mice. TRPV4-IR was largely diminished in the retinas of homozygous TRPV4 transgenic mice. Genetically suppressing TRPV4 expression moderately but significantly enhanced the amplitude of ERG a- and b-waves evoked by scotopic and mesopic lights (0.55 to 200 Rh*rod-1 s-1) and photopic lights (105-106 Rh*rod-1 s-1) compared to wild-type mice in fully dark-adapted conditions. The implicit time evoked by dim lights (0.55 to 200 Rh*rod-1 s-1) was significantly decreased for b-waves and elongated for a-waves in the transgenic mice. ERG b-wave evoked by dim lights is primarily mediated by RBCs, and under voltage-clamp conditions, the latency of the light-evoked cation current in RBCs of the transgenic mice was significantly shorter compared to wild-type mice. About 10% of the transgenic mice had one eye undeveloped, and the percentage was significantly higher than in wild-type mice.
UNASSIGNED: The data indicates that TRPV4 involves ocular development and is expressed and active in outer retinal neurons, and interventions of TRPV4 can variably affect visual signals in rods, cones, RBCs, and cone ON BCs.
摘要：
■哺乳动物视网膜中表达的机械敏感通道是压力升高的效应物，但目前尚不清楚它们的激活如何影响压力相关视网膜疾病的视觉功能。
■这项研究通过免疫组织化学研究了瞬时电位通道香草酸TRPV4在光感受器和杆状双极细胞（RBC）中的作用，共聚焦显微镜，视网膜电图（ERG），和膜片钳技术。
■在光感受器的外部片段中发现了TRPV4免疫反应性（IR），PKCα阳性红细胞和其他BCs的树突和体细胞，丛状层，和野生型小鼠中的视网膜神经节细胞(RGC)。TRPV4-IR在纯合TRPV4转基因小鼠的视网膜中大大减少。在完全黑暗适应的条件下，与野生型小鼠相比，遗传抑制TRPV4的表达适度但显着增强了暗视和中视光（0.55至200Rh*rod-1s-1s-1）和明视光（105-106Rh*rod-1s-1）诱发的ERGa和b波的振幅。在转基因小鼠中，b波显着减少了昏暗光引起的隐含时间（0.55至200Rh*rod-1s-1），而a波则延长了。暗光诱发的ERGb波主要由红细胞介导，在电压钳位条件下，与野生型小鼠相比,转基因小鼠红细胞中光诱发阳离子电流的潜伏期明显缩短.大约10%的转基因小鼠一只眼睛未发育，并且该百分比显著高于野生型小鼠。
■数据表明，TRPV4涉及眼部发育，在视网膜外神经元中表达并活跃，TRPV4的干预可以可变地影响棒中的视觉信号，锥体,红细胞,和锥体在BCs上。
■这项研究通过免疫组织化学研究了瞬时电位通道香草酸TRPV4在光感受器和杆状双极细胞（RBC）中的作用，共聚焦显微镜，视网膜电图（ERG），和膜片钳技术。
■在光感受器的外部片段中发现了TRPV4免疫反应性（IR），PKCα阳性红细胞和其他BCs的树突和体细胞，丛状层，和野生型小鼠中的视网膜神经节细胞(RGC)。TRPV4-IR在纯合TRPV4转基因小鼠的视网膜中大大减少。在完全黑暗适应的条件下，与野生型小鼠相比，遗传抑制TRPV4的表达适度但显着增强了暗视和中视光（0.55至200Rh*rod-1s-1s-1）和明视光（105-106Rh*rod-1s-1）诱发的ERGa和b波的振幅。在转基因小鼠中，b波显着减少了昏暗光引起的隐含时间（0.55至200Rh*rod-1s-1），而a波则延长了。暗光诱发的ERGb波主要由红细胞介导，在电压钳位条件下，与野生型小鼠相比,转基因小鼠红细胞中光诱发阳离子电流的潜伏期明显缩短.大约10%的转基因小鼠一只眼睛未发育，并且该百分比显著高于野生型小鼠。
■数据表明，TRPV4涉及眼部发育，在视网膜外神经元中表达并活跃，TRPV4的干预可以可变地影响棒中的视觉信号，锥体,红细胞,和锥体在BCs上。
