Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan.
Eur J Pharm Sci. 2009 Oct 8;38(3):249-61. doi: 10.1016/j.ejps.2009.07.010. Epub 2009 Aug 5.
Cyclodextrins (CyDs), which are widely used to increase the solubility of drug in pharmaceutical fields, are known to induce hemolysis and cytotoxicity at high concentrations. However, it is still not unclear whether cell death induced by CyDs is apoptosis or not. Therefore, in the present study, we investigated the effects of various kinds of CyDs on apoptosis in the cells such as NR8383 cells, A549 cells and Jurkat cells. Of various CyDs, methylated CyDs inducted cell death under the present experimental conditions, but hydroxypropylated CyDs or sulfobutyl ether-beta-CyD (SBE7-beta-CyD) did not. Of methylated CyDs, 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-CyD) and 2,3,6-tri-O-methyl-beta-cyclodextrin (TM-beta-CyD) markedly caused apoptosis in NR8383 cells, A549 cells and Jurkat cells, through cholesterol depletion in cell membranes. In sharp contrast, 2,6-di-O-methyl-alpha-cyclodextrin (DM-alpha-CyD) and methyl-beta-cyclodextrin (M-beta-CyD) induced cell death in an anti-apoptotic mechanism. DM-beta-CyD induced apoptosis through the inhibition of the activation of PI3K-Akt-Bad pathway. Neither p38 MAP kinase nor p53 was contributed to the induction of apoptosis by DM-beta-CyD. Additionally, DM-beta-CyD significantly decreased mitochondrial transmembrane potential, and then caused the release of cytochrome c from mitochondria to cytosol in NR8383 cells. Furthermore, we confirmed that down-regulation of pro-caspase-3 and activation of caspase-3 after incubation with DM-beta-CyD. These results suggest that of methylated CyDs, DM-beta-CyD, not DM-alpha-CyD, induces apoptosis through the PI3K-Akt-Bad pathway, resulting from cholesterol depletion in lipid rafts of cell membranes.
环糊精（CyDs）广泛用于提高药物在制药领域的溶解度，已知在高浓度下会引起溶血和细胞毒性。然而，CyDs 诱导的细胞死亡是否是细胞凋亡仍然不清楚。因此，在本研究中，我们研究了各种 CyDs 对 NR8383 细胞、A549 细胞和 Jurkat 细胞等细胞凋亡的影响。在各种 CyDs 中，甲基化 CyDs 在本实验条件下诱导细胞死亡，但羟丙基化 CyDs 或磺丁基醚-β-CyD（SBE7-β-CyD）则没有。在甲基化 CyDs 中，2,6-二-O-甲基-β-环糊精（DM-β-CyD）和 2,3,6-三-O-甲基-β-环糊精（TM-β-CyD）通过细胞膜中胆固醇的耗竭，显著导致 NR8383 细胞、A549 细胞和 Jurkat 细胞凋亡。与此形成鲜明对比的是，2,6-二-O-甲基-α-环糊精（DM-α-CyD）和甲基-β-环糊精（M-β-CyD）以抗凋亡机制诱导细胞死亡。DM-β-CyD 通过抑制 PI3K-Akt-Bad 通路的激活诱导细胞凋亡。p38 MAP 激酶和 p53 都没有参与 DM-β-CyD 诱导的细胞凋亡。此外，DM-β-CyD 显著降低线粒体跨膜电位，然后导致细胞色素 c 从 NR8383 细胞的线粒体释放到细胞质。此外，我们证实，用 DM-β-CyD 孵育后，前胱冬肽酶-3 的下调和胱冬肽酶-3 的激活。这些结果表明，在甲基化 CyDs 中，DM-β-CyD，而不是 DM-α-CyD，通过 PI3K-Akt-Bad 通路诱导细胞凋亡，这是由于细胞膜脂筏中胆固醇的耗竭所致。
