Acetylcholine induces Ca2+ signaling in chicken retinal pigmented epithelial cells during dedifferentiation
Acetylcholine induces Ca2+ signaling in chicken retinal pigmented epithelial cells during dedifferentiation
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DOI：
10.1152/ajpcell.00423.2008
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发表时间：
2009-05-01
影响因子：
5.5
通讯作者：
Kosaka, Jun
中科院分区：
文献类型：
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作者：
Sekiguchi-Tonosaki, Mariko;Obata, Masakatsu;Kosaka, Jun
Sekiguchi-Tonosaki M，Obata M，Haruki A，Himi T，Koki-J. Acetylcholine induces Ca2+ signaling in chicken retinal pigmented epithelial cells during dedifferentiation.美国生理学杂志细胞生理学296：C1195-C1206，2009年。首次发表于2009年2月25日; doi：10.1152/ajpcell.00423.2008。视网膜色素上皮细胞通过色素脱失和非上皮形状的去分化中间体将其细胞表型转换为透镜细胞和神经元。因为这些去分化的细胞可以恢复为色素上皮细胞或转分化为透镜细胞和/或神经元，所以它们被认为是透镜和视网膜细胞再生的候选者。本研究的目的是阐明鸡视网膜色素上皮细胞与其去分化中间体之间的信号转导途径。我们监测细胞内钙离子浓度，使用Fluo-4为基础的钙离子光学成像，并专注于细胞对神经递质乙酰胆碱的反应。在视网膜色素上皮细胞和去分化细胞中均观察到毒蕈碱Ca 2+动员，并被阿托品抑制。毒蕈碱依赖的乙酰胆碱反应依赖于细胞内Ca 2+库的Ca 2+释放，这完全被毒胡萝卜素阻断。与此相反，烟碱依赖性乙酰胆碱反应，导致通过L-型钙离子通道的钙内流抑制α-银环蛇毒素和硝苯地平衰减，它只在去分化的中间体中检测到。应用（S）-（-）-BayK 8644升高视网膜色素上皮细胞和去分化中间体的细胞内Ca 2 +;然而，在色素上皮细胞中未观察到烟碱反应。另一种L型钙通道阻滞剂地尔硫卓也能阻断去分化细胞中尼古丁依赖性乙酰胆碱反应，维持视网膜色素上皮细胞的上皮样形态。我们的研究结果表明，在视网膜色素上皮细胞的去分化过程中使用的替代乙酰胆碱信号通路。
Sekiguchi-Tonosaki M, Obata M, Haruki A, Himi T, Kosaka J. Acetylcholine induces Ca2+ signaling in chicken retinal pigmented epithelial cells during dedifferentiation. Am J Physiol Cell Physiol 296: C1195-C1206, 2009. First published February 25, 2009; doi:10.1152/ajpcell.00423.2008.-Retinal pigmented epithelial cells exchange their cellular phenotypes into lens cells and neurons, via depigmented and non-epithelial-shaped dedifferentiated intermediates. Because these dedifferentiated cells can either revert to pigmented epithelial cells or transdifferentiate into lens cells and/or neurons, they are recognized as candidates for lens and retinal cell regeneration. The purpose of the present study was to elucidate the signal transduction pathways between chicken retinal pigmented epithelial cells and their dedifferentiated intermediates. We monitored intracellular Ca2+ concentrations using Fluo-4-based Ca2+ optical imaging and focused on cellular responses to the neurotransmitter acetylcholine. Muscarinic Ca2+ mobilization was observed both in retinal pigmented epithelial cells and in dedifferentiated cells, and was inhibited by atropine. The muscarine-dependent acetylcholine response depended on Ca2+ release from intracellular Ca2+ stores, which was completely blocked by thapsigargin. In contrast, the nicotine-dependent acetylcholine response that led to Ca2+ influx through L-type Ca2+ channels was inhibited by alpha-bungarotoxin and attenuated by nifedipine, and it was detected only in the dedifferentiated intermediates. Application of (S)-(-)-BayK8644 elevated intracellular Ca2+ both in retinal pigmented epithelial cells and in dedifferentiated intermediates; however, the nicotinic response was not observed in pigmented epithelial cells. Another L-type Ca2+ channel blocker, diltiazem, also blocked the nicotine-dependent acetylcholine response in dedifferentiated cells and maintained the epithelial-like morphology of retinal pigmented epithelial cells. Our results indicate that an alternative acetylcholine signaling pathway is used during the dedifferentiation process of retinal pigmented epithelial cells.