阿霉素对人红细胞肌醇脂质代谢的抑制作用。

Inhibition of human erythrocyte inositol lipid metabolism by adriamycin.

作者信息

Thompson M G, Chahwala S B, Hickman J A

出版信息

Cancer Res. 1987 Jun 1;47(11):2799-803.

Abstract

Incubation of human erythrocytes with Adriamycin prevented their morphological transition from discocytes to echinocytes when they were either depleted of ATP or loaded with calcium. This effect was dependent upon drug concentration and cell density. Adriamycin (10(-5) M) prevented, by greater than 90%, the echinocytosis of 10(7) cells/ml (S. B. Chahwala and J. A. Hickman, Cancer Res., 45: 4986-4989, 1985), and 5 X 10(-4) M prevented that of 10(9) cells/ml. There was a poor correlation between the effects of Adriamycin as a modulator of this morphological transition and its potency as an inhibitor of calmodulin. Using inside-out red blood cell vesicles, Adriamycin inhibited calmodulin dependent Ca2+ uptake with a 50% inhibitory concentration of 5 X 10(-4) M. Adriamycin thus differs from other amphipathic drugs, such as those of the phenothiazine class, where inhibition of calmodulin correlated well with effects on erythrocyte morphology (G. A. Nelson, M. L. Andrews, and M. J. Karnovsky, J. Cell Biol., 96: 730-735, 1983). After 12 h of ATP depletion, levels of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] extracted from 10(9) erythrocytes/ml fell by 57% and after 48 h they fell by 97%, changes which were coincident with a 100% transition of morphology to echinocytes. Adriamycin, 5 X 10(-4) M-1 X 10(-3) M, maintained 10(9) cells/ml in a discocyte morphology and maintained PtdIns(4,5)P2 levels at 60-70% of the time zero controls, independently of the size of the fall in PtdIns(4,5)P2 levels. The data suggested that Adriamycin inhibited a discrete pool of PtdIns(4,5)P2 which may be responsible for the maintenance of a discocyte morphology. Neomycin, 10(-3) M, had no effect on the ATP depletion-induced discocyte-echinocyte transition of 10(9) erythrocytes/ml or on the fall in PtdIns(4,5)P2 levels. Adriamycin, like neomycin, prevented the calcium-induced breakdown of erythrocyte membrane vesicle PtdIns(4,5)P2 to inositol trisphosphate (50% inhibitory concentration, 7 X 10(-4) M) but, unlike neomycin (50% inhibitory concentration, 4.25 X 10(-4) M) it was able to inhibit breakdown by 100% at higher concentrations.

摘要

当人红细胞的三磷酸腺苷（ATP）被耗尽或细胞内钙超载时，阿霉素与人红细胞共同孵育可阻止其形态从双凹圆盘状细胞转变为棘状细胞。这种作用取决于药物浓度和细胞密度。阿霉素（10⁻⁵M）可使每毫升10⁷个细胞（S. B. 查瓦拉和J. A. 希克曼，《癌症研究》，45: 4986 - 4989, 1985）的棘状细胞形成减少90%以上，5×10⁻⁴M的阿霉素可使每毫升10⁹个细胞的棘状细胞形成减少。作为这种形态转变调节剂的阿霉素的作用与其作为钙调蛋白抑制剂的效力之间相关性较差。利用内翻式红细胞囊泡，阿霉素抑制钙调蛋白依赖性Ca²⁺摄取，其半数抑制浓度为5×10⁻⁴M。因此，阿霉素不同于其他两亲性药物，如吩噻嗪类药物，在吩噻嗪类药物中，钙调蛋白抑制与对红细胞形态的影响相关性良好（G. A. 纳尔逊、M. L. 安德鲁斯和M. J. 卡尔诺夫斯基，《细胞生物学杂志》，96: 730 - 735, 1983）。ATP耗尽12小时后，每毫升10⁹个红细胞中提取的磷脂酰肌醇4,5 - 二磷酸[PtdIns(4,5)P₂]水平下降57%，48小时后下降97%，这些变化与形态完全转变为棘状细胞同时发生。5×10⁻⁴M - 1×10⁻³M的阿霉素可使每毫升10⁹个细胞维持双凹圆盘状细胞形态，并使PtdIns(4,5)P₂水平维持在零时对照的60 - 70%，与PtdIns(4,5)P₂水平下降幅度无关。数据表明，阿霉素抑制了一组离散的PtdIns(4,5)P₂，这可能负责维持双凹圆盘状细胞形态。10⁻³M的新霉素对每毫升10⁹个红细胞的ATP耗尽诱导的双凹圆盘状细胞 - 棘状细胞转变或PtdIns(4,5)P₂水平下降没有影响。与新霉素一样，阿霉素可阻止钙诱导的红细胞膜囊泡PtdIns(4,5)P₂分解为肌醇三磷酸（半数抑制浓度，7×10⁻⁴M），但与新霉素（半数抑制浓度，4.25×10⁻⁴M）不同的是，在更高浓度下它能够100%抑制分解。