Protochlamydia induces apoptosis of human HEp-2 cells through mitochondrial dysfunction mediated by chlamydial protease-like activity factor.
Protochlamydia induces apoptosis of human HEp-2 cells through mitochondrial dysfunction mediated by chlamydial protease-like activity factor.
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DOI：
10.1371/journal.pone.0056005
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Yamaguchi H
中科院分区：
文献类型：
--
作者：
Matsuo J;Nakamura S;Ito A;Yamazaki T;Ishida K;Hayashi Y;Yoshida M;Takahashi K;Sekizuka T;Takeuchi F;Kuroda M;Nagai H;Hayashida K;Sugimoto C;Yamaguchi H
具有祖先致病性衣原体特征的专门变形虫内共生细菌原衣原体在7 - 14亿年前进化到在原生宿主中生存，如棘阿米巴，但在包括人类在内的脊椎动物中却不能生存。这一观察结果提出了原衣原体与人类细胞之间的相互作用可能导致一种新的细胞病变效应的可能性，从而导致对宿主-寄生虫关系的新见解。先前，我们报道了原衣原体诱导永生的人细胞系HEp-2凋亡。在这项研究中，我们试图阐明这种凋亡的分子机制。我们首先证实，在细菌的刺激下，聚（adp -核糖）聚合酶（PARP）在HEp-2细胞的早期阶段被切割，这取决于细菌的数量。泛caspase抑制剂和caspase-3和-9抑制剂同样抑制HEp-2细胞的凋亡。线粒体膜电位下降也被证实。此外，衣原体蛋白酶样活性因子（CPAF）抑制剂lactacystin可阻断细胞凋亡。细胞松弛素D也能抑制细胞凋亡，这与药物浓度有关，表明细菌进入细胞是诱导细胞凋亡的必要条件。有趣的是，III型耶尔森氏菌抑制剂（ME0052、ME0053和ME0054）对细胞凋亡没有任何影响。我们还证实了本研究中使用的原衣原体具有cpaf基因的同源物，并且沙眼衣原体cpaf活性中心的两个关键残基组氨酸-101和丝氨酸-499是保守的。因此，我们的研究结果表明，原衣原体分泌的CPAF进入线粒体后，通过降低膜电位诱导线粒体功能障碍，随后caspase-9、caspase-3和PARP裂解导致细胞凋亡。更有趣的是，由于沙眼衣原体感染可以阻断细胞凋亡，我们的发现暗示了致病性和原始衣原体之间CPAF的独特特征。
Obligate amoebal endosymbiotic bacterium Protochlamydia with ancestral pathogenic chlamydial features evolved to survive within protist hosts, such as Acanthamoba, 0.7–1.4 billion years ago, but not within vertebrates including humans. This observation raises the possibility that interactions between Protochlamydia and human cells may result in a novel cytopathic effect, leading to new insights into host-parasite relationships. Previously, we reported that Protochlamydia induces apoptosis of the immortalized human cell line, HEp-2. In this study, we attempted to elucidate the molecular mechanism underlying this apoptosis. We first confirmed that, upon stimulation with the bacteria, poly (ADP-ribose) polymerase (PARP) was cleaved at an early stage in HEp-2 cells, which was dependent on the amount of bacteria. A pan-caspase inhibitor and both caspase-3 and -9 inhibitors similarly inhibited the apoptosis of HEp-2 cells. A decrease of the mitochondrial membrane potential was also confirmed. Furthermore, lactacystin, an inhibitor of chlamydial protease-like activity factor (CPAF), blocked the apoptosis. Cytochalasin D also inhibited the apoptosis, which was dependent on the drug concentration, indicating that bacterial entry into cells was required to induce apoptosis. Interestingly, Yersinia type III inhibitors (ME0052, ME0053, and ME0054) did not have any effect on the apoptosis. We also confirmed that the Protochlamydia used in this study possessed a homologue of the cpaf gene and that two critical residues, histidine-101 and serine-499 of C. trachomatis CPAF in the active center, were conserved. Thus, our results indicate that after entry, Protochlamydia-secreted CPAF induces mitochondrial dysfunction with a decrease of the membrane potential, followed by caspase-9, caspase-3 and PARP cleavages for apoptosis. More interestingly, because C. trachomatis infection can block the apoptosis, our finding implies unique features of CPAF between pathogenic and primitive chlamydiae.
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影响因子：
4.2
作者：
Greub G;Collyn F;Guy L;Roten CA
通讯作者：
Roten CA
DOI：
10.1007/978-1-4614-1680-7_8
发表时间：
2012-01-01
期刊：
SELF AND NONSELF
影响因子：
--
作者：
Munoz-Pinedo, Cristina
通讯作者：
Munoz-Pinedo, Cristina
影响因子：
4.4
作者：
Burillo, Almudena;Bouza, Emilio
通讯作者：
Bouza, Emilio
影响因子：
56.9
作者：
Horn, M;Collingro, A;Wagner, M
通讯作者：
Wagner, M
影响因子：
3.2
作者：
Heinz, Eva;Rockey, Daniel D.;Horn, Matthias
通讯作者：
Horn, Matthias