Ebeling J G, Vandenbark G R, Kuhn L J, Ganong B R, Bell R M, Niedel J E
Proc Natl Acad Sci U S A. 1985 Feb;82(3):815-9. doi: 10.1073/pnas.82.3.815.
Activation of cellular protein kinase C appears to be involved in the mechanism by which phorbol diesters induce differentiation of human myeloid leukemia cells (HL-60). Protein kinase C is thought to be physiologically activated by diacylglycerol derived from receptor-mediated phosphatidylinositol hydrolysis. sn-1,2-diacylglycerols with short saturated acyl side chains (C4-C10) were synthesized and found to be potent activators of protein kinase C partially purified from HL-60 cells. These diacylglycerols were also competitive inhibitors of [3H]phorbol dibutyrate binding to the soluble phorbol diester receptor. The most potent diacylglycerol, sn-1,2-dioctanoylglycerol, displaced greater than 90% of [3H]phorbol dibutyrate from the phorbol diester receptor of intact HL-60 cells. Because of probable cellular metabolism of sn-1,2-dioctanoylglycerol, hourly doses were required to maintain persistent occupancy of the phorbol diester binding site. Treatment of HL-60 cells with either phorbol 12-myristate 13-acetate or sn-1,2-dioctanoylglycerol produced identical phosphoprotein changes. Finally, sn-1,2-dioctanoylglycerol induced differentiation of the HL-60 cells into cells with morphologic characteristics of macrophages. Substitution of the hydroxyl group at position 3 with a hydrogen, chloro, or sulfhydryl moiety inactivated sn-1,2-dioctanoylglycerol. These data strengthen the hypothesis that protein kinase C activation plays a role in macrophage differentiation.
细胞蛋白激酶C的激活似乎参与了佛波酯诱导人髓性白血病细胞（HL-60）分化的机制。蛋白激酶C被认为在生理上是由受体介导的磷脂酰肌醇水解产生的二酰基甘油激活的。合成了具有短饱和酰基侧链（C4-C10）的sn-1,2-二酰基甘油，发现它们是从HL-60细胞中部分纯化的蛋白激酶C的有效激活剂。这些二酰基甘油也是[3H]佛波醇二丁酸酯与可溶性佛波酯受体结合的竞争性抑制剂。最有效的二酰基甘油，sn-1,2-二辛酰甘油，从完整HL-60细胞的佛波酯受体上取代了超过90%的[3H]佛波醇二丁酸酯。由于sn-1,2-二辛酰甘油可能在细胞内发生代谢，因此需要每小时给药以维持佛波酯结合位点的持续占据。用佛波醇12-肉豆蔻酸酯13-乙酸酯或sn-1,2-二辛酰甘油处理HL-60细胞产生了相同的磷蛋白变化。最后，sn-1,2-二辛酰甘油诱导HL-60细胞分化为具有巨噬细胞形态特征的细胞。在3位用氢、氯或巯基部分取代羟基会使sn-1,2-二辛酰甘油失活。这些数据强化了蛋白激酶C激活在巨噬细胞分化中起作用的假说。
