Hydroquinone-induced apoptosis in HL-60 cells.
Hydroquinone-induced apoptosis in HL-60 cells.
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DOI：
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发表时间：
2005
影响因子：
2
通讯作者：
H. Terasaka;S. Morshed;K. Hashimoto;H. Sakagami;S. Fujisawa
中科院分区：
文献类型：
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作者：
H. Terasaka;S. Morshed;K. Hashimoto;H. Sakagami;S. Fujisawa
为了阐明氢醌（HQ; 1，4-benzeneurs）诱导人早幼粒白血病细胞株HL-60凋亡的机制，本文研究了HQ诱导的细胞毒性、核小体DNA断裂、超氧化物歧化酶（SOD）的激活、Mn和Cu/ZnSOD mRNA的表达以及caspase-3、-8和-9的激活。SOD富集组分的电泳和活性染色表明，HQ降低MnSOD活化超过Cu/ZnSOD活化，这表明它在细胞凋亡的早期阶段诱导线粒体功能障碍。此外，MnSOD mRNA的表达被抑制到更大的程度比Cu/ZnSOD mRNA，这意味着HQ通过抑制MnSOD诱导引起细胞凋亡。在HQ处理的细胞中，细胞色素c的释放以及半胱天冬酶原-3和-9的激活（而不是半胱天冬酶原-8的激活）发生得更快（早在6小时），这表明HQ激活了细胞凋亡的内在途径。添加抗氧化剂N-乙酰-L-半胱氨酸（NAC）可显著降低HQ的细胞毒性。在对50%的细胞具有细胞毒性的浓度（约0.05 mM）下，HQ激活半胱天冬酶-3;在NAC存在下，这种作用降低。有趣的是，较高浓度的HQ（0.1-0.2 mM）导致直接细胞死亡;然而，当与5 mM NAC组合时，胱天蛋白酶-3的活化强烈增强，表明促进细胞凋亡。HQ/NAC组合对caspase-3的活化表明，细胞内谷胱甘肽合成的前体NAC在HQ诱导的细胞凋亡期间充当助催化剂。
To clarify the mechanisms by which hydroquinone (HQ; 1,4-benzenediol) produces apoptosis, HQ-induced cytotoxicity, intemucleosomal DNA fragmentation, activation of superoxide dismutase (SOD), expression of Mn and Cu/ZnSOD mRNA and activation of caspase-3, -8 and -9 were investigated in the human promyelocytic leukemic cell line HL-60. Electrophoresis and activity staining of the SOD-enriched fraction showed that HQ reduced MnSOD activation more than Cu/ZnSOD activation, suggesting that it induces mitochondrial dysfunction at an early stage of apoptosis. Furthermore, the expression of MnSOD mRNA was suppressed to a greater extent than that of Cu/ZnSOD mRNA, implying that HQ causes apoptosis by inhibiting MnSOD induction. Release of cytochrome c and activation of procaspase-3 and -9, but not of procaspase-8, occurred more rapidly (as early as 6 h) in HQ-treated cells, suggesting that HQ activates the intrinsic pathway of apoptosis. Addition of the antioxidant N-acetyl-L-cysteine (NAC) significantly reduced the cytotoxicity of HQ. At a concentration that was cytotoxic to 50% of the cells (approximately 0.05 mM), HQ activated caspase-3; this effect was reduced in the presence of NAC. Interestingly, higher concentrations of HQ (0.1-0.2 mM) caused direct cell death; however, when combined with 5 mM NAC, the activation of caspase-3 was strongly enhanced, suggesting the promotion of apoptosis. The activation of caspase-3 by HQ/NAC combinations suggests that NAC, a precursor of intracellular glutathione synthesis, acts as a co-catalyst during HQ-induced apoptosis.