Human Trabecular Meshwork Cell Volume Decrease by NO-Independent Soluble Guanylate Cyclase Activators YC-1 and BAY-58-2667 Involves the BKCa Ion Channel
Human Trabecular Meshwork Cell Volume Decrease by NO-Independent Soluble Guanylate Cyclase Activators YC-1 and BAY-58-2667 Involves the BKCa Ion Channel
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DOI：
10.1167/iovs.08-3127
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发表时间：
2009-07-01
影响因子：
4.4
通讯作者：
Ellis, Dorette Z.
中科院分区：
文献类型：
--
作者：
Dismuke, William M.;Sharif, Najam A.;Ellis, Dorette Z.
目的.细胞体积变化与房水流出速率变化之间存在相关性;减少小梁网（TM）细胞体积的药物增加了房水流出速率。本研究探讨了一氧化氮（NO）非依赖性可溶性鸟苷酸环化酶（sGC）激活剂YC-1和BAY-58-2667对TM细胞体积的影响，以及相关的信号转导途径和离子通道。使用钙黄绿素AM荧光染料测量细胞体积，通过共聚焦显微镜检测。使用sGC、3 '，5'-环鸟苷一磷酸（cGMP）、蛋白激酶G（PKG）和BKCa通道的抑制剂和激活剂来表征它们参与YC-1和BAY-58-2667诱导的TM细胞体积调节。通过酶免疫测定法测定cGMP。YC-1（10 nM-200 μ M）和BAY-58-2667（10 nM-100 μ M）各自引起对TM细胞体积的双相作用。YC-1（1 μ M）增加TM细胞体积，但更高的浓度降低TM细胞体积。类似地，BAY-58-2667（100 nM）增加TM细胞体积，但较高浓度降低细胞体积。YC-1诱导的细胞体积减小由8-Br-cGMP模拟，并由sGC抑制剂ODQ、PKG抑制剂（RP）-8-Br-PET-cGMP-S和BKCa通道抑制剂IBTX消除。BAY-58-2667诱导的细胞体积减少由8-Br-cGMP模拟，并由PKG抑制剂和BKCa通道抑制剂消除。与YC-1反应不同，ODQ增强了BAY-58-2667诱导的细胞体积减少。这些数据表明，TM细胞体积的NO非依赖性减少是由sGC/cGMP/PKG途径介导的，并涉及K+流出。（Invest Ophthalmol维斯科学。2009;50：3353-3359）DOI：10.1167/iovs.08-3127
PURPOSE. There is a correlation between cell volume changes and changes in the rate of aqueous humor outflow; agents that decrease trabecular meshwork (TM) cell volume increase the rate of aqueous humor outflow. This study investigated the effects of the nitric oxide (NO)-independent activators of soluble guanylate cyclase (sGC), YC-1, and BAY-58-2667 on TM cell volume and the signal transduction pathways and ion channel involved.METHODS. Cell volume was measured with the use of calcein AM fluorescent dye, detected by confocal microscopy. Inhibitors and activators of sGC, 3',5'-cyclic guanosine monophosphate (cGMP), protein kinase G (PKG), and the BKCa channel were used to characterize their involvement in the YC-1- and BAY-58-2667-induced regulation of TM cell volume. cGMP was assayed by an enzyme immunoassay.RESULTS. YC-1 (10 nM-200 mu M) and BAY-58-2667 (10 nM-100 mu M) each elicited a biphasic effect on TM cell volume. YC-1 (1 mu M) increased TM cell volume, but higher concentrations decreased TM cell volume. Similarly, BAY-58-2667 (100 nM) increased TM cell volume, but higher concentrations decreased cell volume. The YC-1- induced cell volume decrease was mimicked by 8-Br-cGMP and abolished by the sGC inhibitor ODQ, the PKG inhibitor (RP)-8-Br-PET-cGMP-S, and the BKCa channel inhibitor IBTX. The BAY-58-2667-induced cell volume decrease was mimicked by 8-Br-cGMP and was abolished by the PKG inhibitor and the BKCa channel inhibitor. Unlike the YC-1 response, ODQ potentiated the BAY-58-2667-induced decreases in cell volume.CONCLUSIONS. These data suggest that the NO-independent decrease in TM cell volume is mediated by the sGC/cGMP/PKG pathway and involves K+ efflux. (Invest Ophthalmol Vis Sci. 2009;50:3353-3359) DOI:10.1167/iovs.08-3127