Initiation of apoptotic signal by the peroxidation of cardiolipin of mitochondria
Initiation of apoptotic signal by the peroxidation of cardiolipin of mitochondria
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DOI：
10.1196/annals.1293.018
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发表时间：
2004-01-01
期刊：
影响因子：
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通讯作者：
Nakagawa, Y
中科院分区：
文献类型：
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作者：
Nakagawa, Y
在RBL 2 H3细胞（M15细胞）线粒体中过表达磷脂氢过氧化物谷胱甘肽过氧化物酶（PHGPx）可抑制细胞色素c（cyt.c）的释放、caspase-3的激活和2-脱氧葡萄糖（2DG）引起的细胞凋亡，而过表达非营养性PHGPx的细胞（L9细胞）和对照（S1细胞）可诱导细胞凋亡。2DG诱导的细胞凋亡使L9和S1细胞线粒体中过氧化氢水平显著升高。与此相反，在线粒体中的氢过氧化物的产生在M15细胞中得到保护，这也表现出对细胞凋亡的抗性，依托泊苷，星形孢菌素，紫外线照射，放线菌酮，放线菌素D，刺激诱导细胞凋亡的释放cyt.c从线粒体。Cyt.c优先与心磷脂（CL）单层结合，心磷脂是线粒体内膜的特异性磷脂。与心磷脂氢过氧化物（CL-OOH）单层结合的cyt.c的量远低于与CL结合的量。与含有CL的脂质体结合的Cyt.c通过自由基引发剂的过氧化反应释放。腺嘌呤核苷酸转运子（ANT），调节开放和关闭的渗透性转换（PT）孔，可能被灭活后4小时，添加2DG，巧合的是细胞色素C从线粒体中释放后，在骨化诱导的S1细胞。ANT活性被抑制分离的线粒体与脂质体含有CL-OOH的融合。ANT活性在含有10%CL的脂蛋白体中表达，但它被CL-OOH竞争性抑制。这项研究表明，CL过氧化可能有一个启动的作用，在释放cyt.c从内膜，并在PT孔通过ANT线粒体PHGPx的失活的开放可能发挥作用，作为一种抗凋亡因子，保护CL和减少CL-OOH。
Overexpression of phospholipid hydroperoxide glutathione peroxidase (PHGPx) in mitochondria of RBL2H3 cells (M15 cells) prevented the release of cytochrome c (cyt.c), the activation of caspase-3, and apoptosis caused by 2-deoxyglucose (2DG), whereas cells overexpressing nonnutochondrial PHGPx(L9) and control (S1) cells were induced to apoptosis. Hydroperoxide levels in mitochondria of L9 and S1 cells were significantly enhanced by 2DG-induced apoptosis. In contrast, generation of hydroperoxide in mitochondria was protected in M15 cells, which also showed resistance to apoptosis by etoposide, staurosporine, UV irradiation, cycloheximide, and actinomycin D, stimuli that induce apoptosis by the liberation of cyt.c from mitochondria. Cyt.c preferentially binds to the monolayer of cardiolipin (CL), the specific phospholipid of the inner membrane of mitochondria. The amount of cyt.c bound to the monolayer of cardiolipin hydroperoxide (CL-OOH) was much lower than that bound to CL. Cyt.c bound to liposome containing CL was released by peroxidation with a radical initiator. Adenine nucleotide translocator (ANT), which regulates the opening and closing the permeability transition (PT) pore, potentially was inactivated in apoptosis-induced S1 cells 4 h after the addition of 2DG, coincidentally with cyt.c release from mitochondria. ANT activity was suppressed by the fusion of isolated mitochondria with liposomes containing CL-OOH. ANT activity was expressed in proteoliposomes containing 10% CL, but it was competitively inhibited by the addition of CL-OOH. This study suggests that CL peroxidation might have an initiating role in the liberation of cyt.c from the inner membrane, and in the opening of the PT pore via inactivation of ANT Mitochondrial PHGPx might play a role as an anti-apoptotic factor by protecting CL and reducing CL-OOH.