Boya Patricia, Andreau Karine, Poncet Delphine, Zamzami Naoufal, Perfettini Jean-Luc, Metivier Didier, Ojcius David M, Jäättelä Marja, Kroemer Guido
Centre National de la Recherche Scientifique, UMR 8125, Institut Gustave Roussy, Pavillon de Recherche 1, 39 rue Camille-Desmoulins, F-94805 Villejuif, France.
J Exp Med. 2003 May 19;197(10):1323-34. doi: 10.1084/jem.20021952.
A number of diseases are due to lysosomal destabilization, which results in damaging cell loss. To investigate the mechanisms of lysosomal cell death, we characterized the cytotoxic action of two widely used quinolone antibiotics: ciprofloxacin (CPX) or norfloxacin (NFX). CPX or NFX plus UV light (NFX*) induce lysosomal membrane permeabilization (LMP), as detected by the release of cathepsins from lysosomes. Inhibition of the lysosomal accumulation of CPX or NFX suppresses their capacity to induce LMP and to kill cells. CPX- or NFX-triggered LMP results in caspase-independent cell death, with hallmarks of apoptosis such as chromatin condensation and phosphatidylserine exposure on the plasma membrane. LMP triggers mitochondrial membrane permeabilization (MMP), as detected by the release of cytochrome c. Both CPX and NFX* cause Bax and Bak to adopt their apoptotic conformation and to insert into mitochondrial membranes. Bax-/- Bak-/- double knockout cells fail to undergo MMP and cell death in response to CPX- or NFX-induced LMP. The single knockout of Bax or Bak (but not Bid) or the transfection-enforced expression of mitochondrion-targeted (but not endoplasmic reticulum-targeted) Bcl-2 conferred protection against CPX (but not NFX*)-induced MMP and death. Altogether, our data indicate that mitochondria are indispensable for cell death initiated by lysosomal destabilization.
许多疾病是由溶酶体不稳定引起的，这会导致细胞受损死亡。为了研究溶酶体细胞死亡的机制，我们对两种广泛使用的喹诺酮类抗生素的细胞毒性作用进行了表征：环丙沙星（CPX）或诺氟沙星（NFX）。CPX或NFX加紫外线（NFX*）会诱导溶酶体膜通透性增加（LMP），这可通过组织蛋白酶从溶酶体中释放来检测。抑制CPX或NFX在溶酶体中的积累会抑制它们诱导LMP和杀死细胞的能力。CPX或NFX触发的LMP会导致不依赖半胱天冬酶的细胞死亡，具有凋亡的特征，如染色质浓缩和质膜上磷脂酰丝氨酸的暴露。LMP会触发线粒体膜通透性增加（MMP），这可通过细胞色素c的释放来检测。CPX和NFX都会使Bax和Bak呈现凋亡构象并插入线粒体膜。Bax-/- Bak-/-双敲除细胞在响应CPX或NFX诱导的LMP时不会发生MMP和细胞死亡。单独敲除Bax或Bak（但不是Bid）或通过转染强制表达靶向线粒体（但不是内质网）的Bcl-2可提供对CPX（但不是NFX）诱导的MMP和死亡的保护。总之，我们的数据表明线粒体对于由溶酶体不稳定引发的细胞死亡是不可或缺的。
