Bocavirus Infection Induces Mitochondrion-Mediated Apoptosis and Cell Cycle Arrest at G2/M Phase
Bocavirus Infection Induces Mitochondrion-Mediated Apoptosis and Cell Cycle Arrest at G2/M Phase
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DOI：
10.1128/jvi.02094-09
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发表时间：
2010-06-01
影响因子：
5.4
通讯作者：
Qiu, Jianming
中科院分区：
文献类型：
--
作者：
Chen, Aaron Yun;Luo, Yong;Qiu, Jianming
博卡病毒属是细小病毒亚科的一个新分类属。犬博卡病毒微小病毒（MVC）感染在许可的Walter Reed/3873 D（WRD）犬细胞中产生强烈的细胞病变效应。我们系统地描述了MVC感染在WRD细胞中产生的细胞病变效应，即细胞死亡和细胞周期停滞，并仔细研究了MVC感染如何诱导细胞病变效应。我们发现，MVC感染诱导凋亡性细胞死亡，其特征在于Bax易位到线粒体外膜，线粒体外膜电位的破坏，和半胱天冬酶激活。此外，我们观察到半胱天冬酶的激活仅发生在MVC基因组复制时，这表明MVC基因组的复制诱导细胞凋亡。MVC感染还诱导细胞周期从早期的S期逐渐停滞到后期的G（2）/M期，这通过cyclin B1的上调和cdc 2的磷酸化来证实。通过转染MVC感染性克隆的非复制性NS 1敲除突变体以及接种UV照射的MVC，细胞周期停滞在G（2）/M期。与其他细小病毒相比，只有表达的MVC蛋白转染不诱导细胞凋亡或细胞周期停滞。综上所述，我们的结果表明，MVC感染诱导依赖于病毒基因组复制的cervion介导的细胞凋亡，MVC基因组本身能够将细胞周期阻滞在G（2）/M期。我们的研究结果可能有助于阐明博卡病毒感染的分子发病机制。
Bocavirus is a newly classified genus of the family Parvovirinae. Infection with Bocavirus minute virus of canines (MVC) produces a strong cytopathic effect in permissive Walter Reed/3873D (WRD) canine cells. We have systematically characterized the MVC infection-produced cytopathic effect in WRD cells, namely, the cell death and cell cycle arrest, and carefully examined how MVC infection induces the cytopathic effect. We found that MVC infection induces an apoptotic cell death characterized by Bax translocalization to the mitochondrial outer membrane, disruption of the mitochondrial outer membrane potential, and caspase activation. Moreover, we observed that the activation of caspases occurred only when the MVC genome was replicating, suggesting that replication of the MVC genome induces apoptosis. MVC infection also induced a gradual cell cycle arrest from the S phase in early infection to the G(2)/M phase at a later stage, which was confirmed by the upregulation of cyclin B1 and phosphorylation of cdc2. Cell cycle arrest at the G(2)/M phase was reproduced by transfection of a nonreplicative NS1 knockout mutant of the MVC infectious clone, as well as by inoculation of UV-irradiated MVC. In contrast with other parvoviruses, only expression of the MVC proteins by transfection did not induce apoptosis or cell cycle arrest. Taken together, our results demonstrate that MVC infection induces a mitochondrion-mediated apoptosis that is dependent on the replication of the viral genome, and the MVC genome per se is able to arrest the cell cycle at the G(2)/M phase. Our results may shed light on the molecular pathogenesis of Bocavirus infection in general.