Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
Institute of Life Science and Biotechnology, Kyungpook National University, Daegu 702-701, Republic of Korea.
Biochem Biophys Res Commun. 2014 Sep 26;452(3):845-51. doi: 10.1016/j.bbrc.2014.09.015. Epub 2014 Sep 16.
Exposure of human Jurkat T cells to JNK inhibitor IX (JNKi), targeting JNK2 and JNK3, caused apoptotic DNA fragmentation along with G2/M arrest, phosphorylation of Bcl-2, Mcl-1, and Bim, Δψm loss, and activation of Bak and caspase cascade. These JNKi-induced apoptotic events were abrogated by Bcl-2 overexpression, whereas G2/M arrest, cyclin B1 up-regulation, Cdk1 activation, and phosphorylation of Bcl-2 family proteins were sustained. In the concomitant presence of the G1/S blocking agent aphidicolin and JNKi, the cells underwent G1/S arrest and failed to induce all apoptotic events. The JNKi-induced phosphorylation of Bcl-2 family proteins and mitochondrial apoptotic events were suppressed by the Cdk1 inhibitor. Immunofluorescence microscopic analysis revealed that mitotic spindle defect and prometaphase arrest were the underlying factors for the G2/M arrest. These results demonstrate that JNKi-induced mitochondrial apoptosis was caused by microtubule damage-mediated prometaphase arrest, prolonged Cdk1 activation, and phosphorylation of Bcl-2 family proteins in Jurkat T cells.
将人 Jurkat T 细胞暴露于 JNK 抑制剂 IX（JNKi）中，该抑制剂针对 JNK2 和 JNK3，会导致凋亡性 DNA 片段化，同时伴有 G2/M 期阻滞、Bcl-2、Mcl-1 和 Bim 的磷酸化、Δψm 丧失以及 Bak 和半胱天冬酶级联的激活。Bcl-2 的过表达可以阻断这些 JNKi 诱导的凋亡事件，而 G2/M 期阻滞、细胞周期蛋白 B1 的上调、Cdk1 的激活以及 Bcl-2 家族蛋白的磷酸化仍然存在。在 G1/S 阻断剂阿霉素和 JNKi 的同时存在下，细胞经历 G1/S 期阻滞，无法诱导所有的凋亡事件。Cdk1 抑制剂抑制了 JNKi 诱导的 Bcl-2 家族蛋白的磷酸化和线粒体凋亡事件。免疫荧光显微镜分析显示，有丝分裂纺锤体缺陷和前期阻滞是 G2/M 期阻滞的潜在因素。这些结果表明，JNKi 诱导的线粒体凋亡是由微管损伤介导的前期阻滞、Cdk1 的持续激活以及 Jurkat T 细胞中 Bcl-2 家族蛋白的磷酸化引起的。
