Chinese Academy of Sciences, Beijing, China.
Biomed Environ Sci. 2011 Aug;24(4):391-9. doi: 10.3967/0895-3988.2011.04.010.
In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored.
[3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells.
Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone.
The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation.
为了研究曲格列酮诱导 HT29 细胞凋亡的潜在机制，探讨了过氧化物酶体增殖物激活受体γ（PPARγ）和过氧化物酶（POX）诱导的活性氧（ROS）的作用。
采用[3-（4,5）-二甲基噻唑-2-基]-2,5-二苯基四氮唑溴盐（MTT）比色法、流式细胞术检测 Annexin V 和 PI 染色、质粒转染、DCFH 染色检测 ROS 形成、RNA 干扰、RT-PCR 和 RT-QPCR、Western blot 分析等方法，研究曲格列酮的凋亡作用及 PPARγ 通路和 POX 诱导的 ROS 形成在 HT29 细胞中的潜在作用。
曲格列酮通过诱导细胞凋亡抑制 HT29 细胞的生长。在此过程中，ROS 形成、POX 表达和细胞色素 c 释放等线粒体相关途径增加，这一过程可被 PPARγ 的特异性拮抗剂 GW9662 所抑制。这些结果表明，曲格列酮诱导的细胞凋亡中 POX 的上调和 ROS 的形成是受 PPARγ 调节的。此外，在曲格列酮处理的 HT29 细胞中使用 POX siRNA 抑制 ROS 和凋亡表明，POX 在 ROS 形成和曲格列酮诱导的 PPARγ 依赖性凋亡中是必需的。
本研究结果表明，曲格列酮诱导的凋亡是通过 POX 诱导的 ROS 形成介导的，至少部分是通过 PPARγ 激活。
