Choi Young Ki, Kim Tae-Kyung, Kim Chul-Joong, Lee Joong-Seob, Oh Se-Young, Joo Han Soo, Foster Douglas N, Hong Ki-Chang, You Seungkwon, Kim Hyunggee
College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju 361-711, Korea.
Exp Mol Med. 2006 Feb 28;38(1):11-7. doi: 10.1038/emm.2006.2.
The mitochondrial pathway of swine influenza virus (SIV)-induced apoptosis was investigated using porcine kidney (PK-15) cells, swine testicle (ST) cells, and HeLa cervical carcinoma cells which are known not to support viral replication. As judged by cell morphology, annexin V staining, and DNA fragmentation, PK-15 and ST cells infected with three different subtypes of SIV (H1N1, H3N2, and H1N2) were obviously killed by apoptosis, not necrosis. SIV infection in PK-15 and HeLa cells was shown to decrease the cellular levels of Bcl-2 protein compared to that of mock-infected control cells at 24 h post-infection, whereas expression levels of Bax protein increased in the PK-15 cells, but did not increase in HeLa cells by SIV infection. Cytochrome c upregulation was also observed in cytosolic fractions of the PK-15 and HeLa cells infected with SIV. Apoptosome (a multi-protein complex consisting of cytochrome c, Apaf-1, caspase-9, and ATP) formation was confirmed by immunoprecipitation using cytochrome c antibody. Furthermore, SIV infection increased the cellular levels of TAJ, an activator of the JNK- stressing pathway, and the c-Jun protein in the PK-15 and HeLa cells. Taken together, these results suggest that the mitochondrial pathway should be implicated in the apoptosis of PK-15 cells induced by SIV infection.
利用猪肾（PK - 15）细胞、猪睾丸（ST）细胞以及已知不支持病毒复制的人宫颈癌HeLa细胞，研究了猪流感病毒（SIV）诱导细胞凋亡的线粒体途径。通过细胞形态、膜联蛋白V染色和DNA片段化判断，感染三种不同亚型SIV（H1N1、H3N2和H1N2）的PK - 15和ST细胞明显因凋亡而非坏死死亡。与感染后24小时的 mock 感染对照细胞相比，PK - 15和HeLa细胞中的SIV感染显示出细胞中Bcl - 2蛋白水平降低，而PK - 15细胞中Bax蛋白的表达水平增加，但SIV感染并未使HeLa细胞中的Bax蛋白表达水平增加。在感染SIV的PK - 15和HeLa细胞的胞质组分中也观察到细胞色素c上调。通过使用细胞色素c抗体进行免疫沉淀证实了凋亡小体（一种由细胞色素c、凋亡蛋白酶激活因子 - 1、半胱天冬酶 - 9和ATP组成的多蛋白复合物）的形成。此外，SIV感染增加了PK - 15和HeLa细胞中TAJ（JNK应激途径的激活剂）和c - Jun蛋白的细胞水平。综上所述，这些结果表明线粒体途径与SIV感染诱导的PK - 15细胞凋亡有关。
