共 61 条
Mediating of caspase-independent apoptosis by cadmium through the mitochondria-ROS pathway in MRC-5 fibroblasts
被引:141
作者:
Shih, CM
Ko, WC
Wu, JS
Wei, YH
Wang, LF
Chang, EE
Lo, TY
Cheng, HH
Chen, CT
机构:
[1] Taipei Med Univ, Sch Med, Dept Biochem, Taipei 110, Taiwan
[2] Taipei Med Univ, Grad Inst Pharmacol, Taipei, Taiwan
[3] Natl Yang Ming Univ, Dept Biochem, Taipei 112, Taiwan
[4] Natl Yang Ming Univ, Ctr Cellular & Mol Biol, Taipei 112, Taiwan
关键词:
cadmium;
caspase;
ROS;
AIF;
mitochondria;
ETC;
MPTP;
D O I:
10.1002/jcb.10761
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
Cadmium (Cd) is an environmental pollutant of global concern with a 10-30-year biological half-life in humans. Accumulating evidence suggests that the lung is one of the major target organs of inhaled Cd compounds. Our previous report demonstrated that 100 muM Cd induces MRC-5 cells, normal human lung fibroblasts, to undergo caspase-independent apoptosis mediated by mitochondrial membrane depolarization and translocation of apoptosis-inducing factor (AIF) from mitochondria into the nucleus. Here, using benzyloxycarbonyl-Val-Ala-Asp-(ome) fluoromethyl ketone (Z-VAD.fmk) as a tool, we further demonstrated that Cd could induce caspase-independent apoptosis at concentrations varied from 25 to 150 muM, which was modulated by reactive oxygen species (ROS) scavengers, such as N-acetylcysteine (NAC), mannitol, and tiron, indicating that ROS play a crucial role in the apoptogenic activity of Cd. Consistent with this notion, the intracellular hydrogen peroxide (H2O2) was 2.9-fold elevated after 3 h of Cd treatment and diminished rapidly within 1 h as detected by flow cytometry with 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Using inhibitors of the mitochondrial electron transport chain (ETC) (oligomycin A and rotenone for complex I and V, respectively) and mitochondrial permeability transition pore (MPTP) (cyclosporin A and aristolochic acid), we coincidently found the ROS production, mitochondrial membrane depolarization, and apoptotic content were almost completely or partially abolished. As revealed by confocal microscopy staining with chloromethyl-X-rosamine (CMXRos) and an anti-AIF antibody, the collapse of mitochondrial membrane potential induced by Cd (3 h-treatment) was a prelude to the translocation of caspase-independent pro-apoptotic factor, AIF, into the nucleus (after 4 h of Cd treatment). In summary, this study demonstrated that, in MRC-5 fibroblasts, Cd induced caspase-independent apoptosis through a mitochondria-ROS pathway. More importantly, we provide several lines of evidence supporting a role of mitochondrial ETC and MPTP in the regulation of caspase-independent cell death triggered by Cd.
引用
收藏
页码:384 / 397
页数:14
相关论文