Decreased gap junctional communication in neurobiotin microinjected lens epithelial cells after taxol treatment
Decreased gap junctional communication in neurobiotin microinjected lens epithelial cells after taxol treatment
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DOI：
10.1007/s00429-005-0456-z
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发表时间：
2005-06-01
期刊：
影响因子：
--
通讯作者：
Meller, K
中科院分区：
文献类型：
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作者：
Giessmann, D;Theiss, C;Meller, K
该研究的目的是在实验诱导培养的牛晶状体上皮细胞中微管聚集后检查间隙连接介导的细胞间通讯。晶状体细胞之间的细胞间通讯似乎对于正常晶状体稳态至关重要。然而，在导致微管成束的条件下，尚未对通过间隙连接维持直接离子和代谢物交换及其对细胞骨架微管的量化依赖性进行研究。因此，在各种条件下将神经生物素显微注射到单个细胞中后，对邻近晶状体上皮细胞的代谢耦合进行了定量。在对照中，密集的间隙连接介导的细胞间通讯可以通过微注射神经生物素的染料扩散来记录。相比之下，紫杉醇治疗1-3天会损害但并未完全阻断间隙连接介导的细胞间通讯。紫杉醇耗尽后，细胞间通讯完全恢复。此外，共聚焦激光扫描显微镜和快速冷冻深蚀刻电子显微镜显示，肌动蛋白丝从核周细胞质中移位，并伴有紫杉醇处理后微管的异常聚集，包括连接蛋白43从细胞质到质膜的易位受阻。用诺考达唑孵育细胞会破坏微管网络，同时质膜整合连接蛋白 43 明显减少，并且染料扩散显着受损。因此，在晶状体上皮细胞中，由连接蛋白43形成的间隙连接处的细胞间通讯取决于通过连接蛋白易位至质膜的微管网络的完整性。
The aim of the study was to examine gap-junction-mediated intercellular communication after experimentally induced aggregations of microtubules in cultured bovine lens epithelial cells. Intercellular communication between lens cells appears to be crucial for normal lens homeostasis. However, investigations on the maintenance of direct ion and metabolite exchange via gap junctions and its quantified dependency of cytoskeletal microtubules have not been available under conditions leading to bundling of microtubules. Thus, metabolic coupling of neighboring lens epithelial cells was quantified following microinjections of neurobiotin into single cells under various conditions. In controls, intensive gap-junction-mediated intercellular communication could be documented by dye-spreading of microinjected neurobiotin. In contrast, taxol treatment for 1-3 days impaired, but did not completely block gap-junction-mediated intercellular communication. After depletion of taxol, a complete recovery of intercellular communication was achieved. In addition, confocal laser scanning microscopy and rapid-freeze deep-etch electron microscopy revealed a displacement of actin-filaments from the perinuclear cytoplasm, accompanied by an abnormal aggregation of microtubules after taxol treatment, including impeded translocation of connexin 43 from the cytoplasm into the plasma membrane. Incubation of cells with nocodazole destroyed the microtubule network, accompanied by a clear reduction of plasma-membrane-integrated connexin 43 and significant impairment of dye spreading. Thus, in lens epithelial cells intercellular communication at gap junctions made by connexin 43 depends on the integrity of the microtubule network through the translocation of connexins to the plasma membrane.