Functional IP3- and ryanodine-sensitive calcium stores in presynaptic varicosities of NG108-15 (rodent neuroblastoma x glioma hybrid) cells.
Functional IP3- and ryanodine-sensitive calcium stores in presynaptic varicosities of NG108-15 (rodent neuroblastoma x glioma hybrid) cells.
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NG108-15（啮齿动物神经母细胞瘤 x 神经胶质瘤杂种）细胞突触前静脉曲张中功能性 IP3 和兰尼定敏感钙储存。
DOI：
10.1111/j.1469-7793.2000.00307.x
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Nichols,RA
中科院分区：
文献类型：
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作者：
Rondé,P;Dougherty,JJ;Nichols,RA
1检测了神经元细胞系NG 108 -15（一种胆碱能神经母细胞瘤细胞×神经胶质瘤细胞的杂交细胞，能够支配横纹肌管）的突触前静脉曲张中肌醇1，4的存在，5-三磷酸盐（IP 3）敏感和Ca 2+激活（ryanodine-敏感）Ca 2+商店使用Ca 2+的共聚焦显微镜成像2使用免疫细胞化学获得了NG 108 -15静脉曲张中IP 3受体和兰尼碱受体存在的初步证明。3用缓激肽处理NG 108 -15细胞（0.1 μM），其受体与IP 3的产生有关，以及单独的咖啡因（10 mM），内质网兰尼碱受体的激活剂，导致静脉曲张中[Ca 2 +] i的显著增加。在使用咖啡因（10 mM）排空兰尼碱敏感的Ca 2+储存后，静脉曲张中[Ca 2 +] i的4K+诱发变化减少（52%），但不受预先使用毒胡萝卜素（1 μM）耗尽IP 3敏感性Ca 2+库的影响。5缓激肽诱导的[Ca 2 +] i变化在使用毒胡萝卜素（1 μM）耗尽IP 3敏感性Ca 2+库后被消除，并且通过预先使用咖啡因排空ryanodine敏感性Ca 2+库（6当NG 108 -15细胞的静脉曲张与共培养的大鼠后肢肌管形成突触连接时，获得了相同的结果。7总的来说，结果表明，在静脉曲张中，IP 3通路的激活引起了Ca 2+从IP 3敏感性储存中的释放，反过来，通过Ca 2+诱导的Ca 2+释放，继发性地诱导Ca 2+从ryanodine敏感性储存库释放，并且去极化诱导的Ca 2+内流仅从ryanodine敏感性储存库诱发Ca 2+诱导的Ca 2+释放。因此，功能性的内部Ca 2+商店是在这个神经细胞系中突触前静脉曲张的固有组成部分。
1Presynaptic varicosities of the model neuronal cell line NG108–15, a cholinergic neuroblastoma cell × glioma cell hybrid capable of innervating striated myotubes, were examined for the presence of inositol 1,4,5‐trisphosphate (IP3)‐sensitive and Ca2+‐activated (ryanodine‐sensitive) Ca2+stores using confocal microscopic imaging of Ca2+‐sensitive fluorescent dye loaded into the cells.2Initial demonstration of the presence of IP3receptors and ryanodine receptors in the NG108–15 varicosities was obtained using immunocytochemistry.3Treatment of NG108–15 cells with bradykinin (0.1 μM), whose receptor is linked to IP3generation, and separately, caffeine (10 mM), an activator of endoplasmic reticulum ryanodine receptors, resulted in substantial increases in [Ca2+]iin the varicosities.4K+‐evoked changes in [Ca2+]iin the varicosities were reduced (52 %) after emptying the ryanodine‐sensitive Ca2+store using caffeine (10 mM), but were not affected by prior depletion of the IP3‐sensitive Ca2+store using thapsigargin (1 μM).5Bradykinin‐induced changes in [Ca2+]iwere abolished following depletion of the IP3‐sensitive Ca2+store using thapsigargin (1 μM) and were reduced (72 %) by prior emptying of the ryanodine‐sensitive Ca2+store with caffeine (10 mM).6The same results were obtained when the varicosities of the NG108–15 cells had formed synaptic junctions with co‐cultured rat hindlimb myotubes.7Taken together, the results suggest that, in the varicosities, activation of the IP3pathway evoked the release of Ca2+from the IP3‐sensitive store, which, in turn, secondarily induced the release of Ca2+from the ryanodine‐sensitive store via Ca2+‐induced Ca2+release, and that depolarization‐induced Ca2+entry evoked Ca2+‐induced Ca2+release only from the ryanodine‐sensitive store. Thus, functional internal Ca2+stores are inherent components of presynaptic varicosities in this neural cell line.