Screening of gap junction antagonists on dye coupling in the rabbit retina
Screening of gap junction antagonists on dye coupling in the rabbit retina
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DOI：
10.1017/s0952523807070472
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发表时间：
2007-07-01
影响因子：
1.9
通讯作者：
Massey, Stephen C.
中科院分区：
文献类型：
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作者：
Pan, Feng;Mills, Stephen L.;Massey, Stephen C.
视网膜中的许多细胞类型通过间隙连接偶联，因此迫切需要有效且可逆的间隙连接拮抗剂。我们筛选了一系列潜在的间隙连接拮抗剂，通过评估其对A型水平细胞网络中染料偶联的影响。我们评估了以下化合物：甲哌那酸（MFA）、甲氟喹、2-氨基乙基二苯基硼酸酯（2-APB）、18-α-甘氨酰菲次酸、18-β-甘草次酸（18-β-GA）、瑞替莫酸、氟灭酸、尼氟灭酸和甘珀酸。通过测量神经生物素的扩散系数来确定每种药物的功效（米尔斯和梅西，1998）。MFA、18-beta-GA、2-APB和甲氟喹是最有效的拮抗剂，在200 μ M的浓度下完全消除A型水平细胞偶联。硝氟灭酸、氟灭酸和甘珀酸的效力较低。此外，甘珀酸很难洗掉，也可能是有害的，因为视网膜变得不透明和肿胀。MFA、18-beta-GA、2-APB和甲氟喹也阻断了B型水平细胞和All无长突细胞的偶联。由于这些细胞类型表达不同的连接蛋白，这表明拮抗剂在几种不同类型的间隙连接中相对无选择性。应该强调的是，MFA是水溶性的，其对染料偶联的影响是容易可逆的。相比之下，除甘珀酸之外的其他间隙连接拮抗剂需要DMSO来制备储备溶液，并且难以在阻断A型HC中偶联所需的剂量下从制剂中洗出。结合效力，水溶性和可逆性表明，MFA可能是一个有用的化合物来操纵间隙连接耦合。
Many cell types in the retina are coupled via gap junctions and so there is a pressing need for a potent and reversible gap junction antagonist. We screened a series of potential gap junction antagonists by evaluating their effects on dye coupling in the network of A-type horizontal cells. We evaluated the following compounds: meclofenamic acid (MFA), mefloquine, 2-aminoethyldiphenyl borate (2-APB), 18-alpha-glycyffhetinic acid, 18-beta-glycyrrhetinic acid (18-beta-GA), retimoic acid, flufenamic acid, niflumic acid, and carbenoxolone. The efficacy of each drug was determined by measuring the diffusion coefficient for Neurobiotin (Mills & Massey, 1998). MFA, 18-beta-GA, 2-APB and mefloquine were the most effective antagonists, completely eliminating A-type horizontal cell coupling at a concentration of 200 mu M. Niflumic acid, flufenamic acid, and carbenoxolone were less potent. Additionally, carbenoxolone was difficult to wash out and also may be harmful, as the retina became opaque and swollen. MFA, 18-beta-GA, 2-APB and mefloquine also blocked coupling in B-type horizontal cells and All amacrine cells. Because these cell types express different connexins, this suggests that the antagonists were relatively non-selective across several different types of gap junction. It should be emphasized that MFA was water-soluble and its effects on dye coupling were easily reversible. In contrast, the other gap junction antagonists, except carbenoxolone, required DMSO to make stock solutions and were difficult to wash out of the preparation at the doses required to block coupling in A-type HCs. The combination of potency, water solubility and reversibility suggest that MFA may be a useful compound to manipulate gap junction coupling.