Song S K, Choi S Y, Kim K T
Department of Life Science, Pohang University of Science and Technology, Republic of Korea.
Biochem Pharmacol. 1998 Sep 1;56(5):561-7. doi: 10.1016/s0006-2952(97)00660-6.
Treatment of HL-60 cells with thapsigargin, a microsomal Ca2+/ATPase inhibitor, led to depletion of intracellular calcium stores followed by capacitative calcium entry. Stimulation of adenylyl cyclase with forskolin enhanced thapsigargin-induced Ca2+ influx. The forskolin effect was confirmed by enhanced fluorescence quenching induced by Mn2+ entry into fura-2 loaded cells. 1,9-Dideoxy-forskolin, an inactive analog of forskolin, did not affect capacitative calcium entry. On the other hand, phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, inhibited thapsigargin-induced Ca2+ entry. Histamine and prostaglandin E2 (PGE2) elevated intracellular adenosine 3':5'-cyclic monophosphate (cAMP) levels and enhanced the thapsigargin-induced capacitative calcium entry. Incubation with N-[2-(p-bromocynnamylamino)ethyl]-5-isoquinolinesulfonamide (H89), an inhibitor of protein kinase A (PKA), blocked the forskolin effect, and GF109203X, an inhibitor of protein kinase C (PKC), blocked the phorbol 12-myristate 13-acetate effect. The results suggest that protein kinase A regulates capacitative calcium entry positively, but that protein kinase C regulates Ca2+ influx negatively. Furthermore, after differentiation of HL-60 promyelocytes with dimethylsulfoxide to granulocytes, the inhibitory effect of phorbol 12-myristate 13-acetate became more pronounced, whereas the stimulatory effect of prostaglandin E2 did not change. This result suggests that the regulation of capacitative calcium entry by protein kinase C and protein kinase A develops differently during differentiation.
用毒胡萝卜素（一种微粒体Ca2+/ATP酶抑制剂）处理HL-60细胞，导致细胞内钙库耗竭，随后出现容量性钙内流。用福斯高林刺激腺苷酸环化酶可增强毒胡萝卜素诱导的Ca2+内流。Mn2+进入负载fura-2的细胞所诱导的荧光猝灭增强证实了福斯高林的作用。1,9-二脱氧福斯高林（福斯高林的一种无活性类似物）不影响容量性钙内流。另一方面，蛋白激酶C的激活剂佛波酯12-肉豆蔻酸酯13-乙酸酯（PMA）抑制毒胡萝卜素诱导的Ca2+内流。组胺和前列腺素E2（PGE2）提高细胞内3':5'-环磷酸腺苷（cAMP）水平，并增强毒胡萝卜素诱导的容量性钙内流。用蛋白激酶A（PKA）抑制剂N-[2-（对溴肉桂酰胺基）乙基]-5-异喹啉磺酰胺（H89）孵育可阻断福斯高林的作用，用蛋白激酶C（PKC）抑制剂GF1092**03X可阻断佛波酯12-肉豆蔻酸酯13-乙酸酯的作用。结果表明，蛋白激酶A正向调节容量性钙内流，而蛋白激酶C负向调节Ca2+内流。此外，用二甲基亚砜将HL-60早幼粒细胞分化为粒细胞后，佛波酯12-肉豆蔻酸酯13-乙酸酯的抑制作用变得更加明显，而前列腺素E2的刺激作用没有改变。这一结果表明，蛋白激酶C和蛋白激酶A对容量性钙内流的调节在分化过程中发展方式不同。
