OXIDASE ACTIVATION IN INDIVIDUAL NEUTROPHILS IS DEPENDENT ON THE ONSET AND MAGNITUDE OF THE CA-2+ SIGNAL
OXIDASE ACTIVATION IN INDIVIDUAL NEUTROPHILS IS DEPENDENT ON THE ONSET AND MAGNITUDE OF THE CA-2+ SIGNAL
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DOI：
10.1016/0143-4160(90)90020-u
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发表时间：
1990-11-01
期刊：
影响因子：
4
通讯作者：
CAMPBELL, AK
中科院分区：
文献类型：
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作者：
HALLETT, MB;DAVIES, EV;CAMPBELL, AK
使用Fura-2负载的中性粒细胞的单细胞比率成像，我们证明了氧化酶反应的异质性和稳定性源于胞质游离Ca 2+信号的时间和幅度的变化。 来自单个细胞的Ca 2+信号可分为四种类型：（a）1型，在6 s内发生的Ca 2+瞬时升高;（B）2型，振荡的胞质游离Ca 2 +;（c）3型，显著延迟（21-56 s）的潜伏Ca 2+瞬时升高;和（d）4型，无显著Ca 2+升高。 这些反应类型在1 μ M f-met-leu-phe肽刺激（n = 27）时分别占群体的约41%、15%、26%和18%，在0.1 μ M f-met-leu-phe肽刺激（n = 52）时分别占52.5%、15%、11.5%和21%。 中性粒细胞中的氧化酶，其中胞质游离Ca 2+浓度上升到大于250 nM总是被激活。 在细胞外Ca 2+的存在下，胞质Ca 2+均匀地在整个细胞中上升，而在细胞外Ca 2+的情况下，在大约30%的细胞中观察到局部化的Ca 2+“云”。 当超过250 nM Ca 2+阈值时，氧化酶的局部活化伴随着Ca 2+“云”的存在。 因此，本文提供的数据表明，在单个中性粒细胞中，细胞溶质游离Ca 2+升高至250 nM阈值以上与氧化酶激活之间存在紧密耦合。
Using single-cell ratio imaging of Fura-2-loaded neutrophils, we demonstrate that the heterogeneity and asynchrony of the oxidase response originates from variability in the timing and magnitude of the cytosolic free Ca2+ signal. The Ca2+ signals from individual cells could be classified into four types: (a) type 1, a transient rise in Ca2+ occurring within 6 s; (b) type 2, an oscillating cytosolic free Ca2+; (c) type 3, a latent Ca2+ transient significantly delayed (21-56 s); and (d) type 4, no significant Ca2+ rise. These response types accounted for approximately 41%, 15%, 26% and 18% of the population respectively for stimulation with 1-mu-M f-met-leu-phe peptide (n = 27) and 52.5%, 15%, 11.5% and 21% respectively for 0.1-mu-M f-met-leu-phe peptide (n = 52). The oxidase in neutrophils in which the cytosolic free Ca2+ concentration rose to greater than 250 nM always became activated. In the presence of extracellular Ca2+, cytosolic Ca2+ rose uniformly throughout the cell, whereas in the absence of extracellular Ca2+, a localised Ca2+ 'cloud' was observed in approximately 30% of cells. A localised activation of the oxidase accompanied the presence of the Ca2+ 'cloud' when the 250 nM Ca2+ threshold was exceeded. The data presented here therefore demonstrate a tight coupling in individual neutrophils between an elevation in cytosolic free Ca2+ above a threshold of 250 nM and activation of the oxidase.