Baud L, Goetzl E J, Koo C H
Howard Hughes Medical Institute, University of California Medical Center, San Francisco 94143-0724.
J Clin Invest. 1987 Oct;80(4):983-91. doi: 10.1172/JCI113192.
The C6-sulfidopeptide leukotrienes C4 (LTC4) and D4 (LTD4) evoked increases in the cytosolic concentration of intracellular calcium ([Ca+2]i) in dimethylsulfoxide-differentiated HL-60 cells, as assessed by the fluorescence of quin-2. The increases in [Ca+2]i reached a peak within 15-90 s, attained 50% of the maximum level at 1.2 nM LTD4 and 60 nM LTC4, were greater in maximal magnitude for LTD4 than LTC4, and subsided in 5-7 min. Flow cytometric evaluation of the LTD4-induced increases in [Ca+2]i, reflected in increases in the fluorescence of intracellular indo-1, revealed that a mean of 77% of differentiated HL-60 cells responded, as contrasted with lesser increases in only 50% of undifferentiated HL-60 cells. The capacity of pretreatment of HL-60 cells with LTD4 to prevent subsequent responses of [Ca+2]i to LTC4 and LTD4, and the finding that the serine-borate inhibitor of conversion of LTC4 to LTD4 suppressed concurrently both LTC4-induced rises in [Ca+2]i and increases in adherence to Sephadex G-25 indicated that the responses of HL-60 cells to LTC4 required conversion to LTD4. That pertussis toxin and a chemical antagonist of LTD4 reduced the [Ca+2]i response suggested a dependence on LTD4 receptors. The LTD4-induced increases in [Ca+2]i were dependent on extracellular calcium and diminished by lanthanum, but not affected by nifedipine nor associated with changes in membrane potential, as measured with the fluorescent probe 3,3'-dipentyloxacarbocyanine. Thus, the increase in [Ca+2]i in HL-60 cells, which is coupled to an increase in adherence, appears to involve LTD4 receptor-specific and voltage-independent calcium channels in the plasma membrane.
通过喹啉-2荧光评估发现，在二甲基亚砜分化的HL-60细胞中，C6-硫化肽白三烯C4（LTC4）和D4（LTD4）可引起细胞内钙离子（[Ca+2]i）胞质浓度升高。[Ca+2]i升高在15 - 90秒内达到峰值，在1.2 nM LTD4和60 nM LTC4时达到最大水平的50%，LTD4引起的[Ca+2]i升高幅度在最大值时大于LTC4，且在5 - 7分钟内消退。通过流式细胞术评估LTD4诱导的[Ca+2]i升高，表现为细胞内吲哚-1荧光增加，结果显示平均77%的分化HL-60细胞有反应，相比之下，未分化的HL-60细胞只有50%有较小幅度的增加。用LTD4预处理HL-60细胞可防止随后[Ca+2]i对LTC4和LTD4的反应，并且发现LTC4转化为LTD4的丝氨酸 - 硼酸盐抑制剂同时抑制LTC4诱导的[Ca+2]i升高和对葡聚糖凝胶G - 25的黏附增加，这表明HL-60细胞对LTC4的反应需要转化为LTD4。百日咳毒素和LTD4的化学拮抗剂降低了[Ca+2]i反应，提示其依赖于LTD4受体。LTD4诱导的[Ca+2]i升高依赖于细胞外钙，可被镧减弱，但不受硝苯地平影响，也与用荧光探针3,3'-二戊基氧杂羰花青测量的膜电位变化无关。因此，HL-60细胞中与黏附增加相关的[Ca+2]i升高似乎涉及质膜中LTD4受体特异性且与电压无关的钙通道。
