Hyperthermia-induced apoptosis in Tca8113 cells is inhibited by heat shock protein 27 through blocking phospholipid scramblase 3 phosphorylation
Hyperthermia-induced apoptosis in Tca8113 cells is inhibited by heat shock protein 27 through blocking phospholipid scramblase 3 phosphorylation
复制标题
热休克蛋白27通过阻断磷脂扰乱酶3磷酸化来抑制Tca8113细胞热诱导的细胞凋亡
DOI：
10.3109/02656731003793393
复制
发表时间：
2010-01-01
影响因子：
3.1
通讯作者：
He, Yong-Wen
中科院分区：
文献类型：
--
作者：
Jiang, Wen;Bian, Li;He, Yong-Wen
目的：热疗通过线粒体凋亡途径诱导肿瘤细胞凋亡；然而，这一过程背后的信号转导机制仍需要充分阐明。磷脂超燃酶3（磷脂超燃酶3，PLS3）是蛋白激酶C-δ (PKC-δ)的靶点，存在于线粒体中，在细胞凋亡反应的调控中起关键作用。活化的PLS3促进了心磷脂（CL）从线粒体内膜向线粒体外膜外叶的易位，并引发细胞凋亡。材料与方法：用Lipofectamine 2000转染或共转染舌鳞癌Tca8113细胞，质粒分别为pCMV-6×His-PLS3、pCMV-6×His-PLS3 （T21A）、pHA-PKC-δ、pHA-PKC-δ- kd （K376R）、pHA-Hsp27和空对照质粒pcDNA3.1。转染后的细胞在43°C水浴中加热20、40、60 min。流式细胞术检测细胞凋亡和线粒体心磷脂的再分布。western blotting检测PLS3、PKC-δ、Hsp27、PLS3磷酸化和PLS3/PKC-δ相互作用。结果：我们的研究结果表明，野生型PLS3水平升高，而PLS3 （T21A）突变体水平升高，能够增加高温诱导的CL易位和细胞凋亡。野生型PKC-δ促进PLS3磷酸化、PKC-δ/PLS3相互作用和CL易位，从而促进细胞凋亡。相反，热休克蛋白27 （Hsp27）阻断PKC-δ诱导的PLS3磷酸化，抑制PKC-δ/PLS3相互作用和CL易位，抑制细胞凋亡。结论：我们的研究结果表明PKC-δ磷酸化PLS3参与了Tca8113细胞高温诱导的凋亡信号转导通路，Hsp27阻断该通路抑制高温诱导的细胞凋亡。
Purpose: Hyperthermia induces tumour cell apoptosis through the mitochondrial apoptotic pathway; however, the signal transduction mechanism underlying this process still needs to be fully elucidated. Phospholipid scramblase 3 (PLS3), a target of protein kinase C-δ (PKC-δ), resides in mitochondria and plays pivotal roles in regulating apoptotic response. Activated PLS3 facilitates cardiolipin (CL) translocation from the mitochondrial inner membrane to the outer leaflet of the mitochondrial outer membrane and triggers apoptosis. Materials and methods: The tongue squamous cell carcinoma Tca8113 cells were transfected or co-transfected using Lipofectamine 2000 with plasmids pCMV-6×His-PLS3, pCMV-6×His-PLS3 (T21A), pHA-PKC-δ, pHA-PKC-δ-KD (K376R), pHA-Hsp27, and empty control plasmid pcDNA3.1. The transfected cells were heated in water bath at 43°C for 20 min, 40 min and 60 min. Assessments of apoptosis and redistribution of mitochondrial cardiolipin were performed by flow cytometry. PLS3, PKC-δ, Hsp27, phosphorylation of PLS3 and PLS3/PKC-δ interaction were detected by western blotting. Results: In our study the results show that elevated levels of the wild-type PLS3, but not the PLS3 (T21A) mutant, is able to increase hyperthermia-induced CL translocation and apoptosis. Wild-type PKC-δ facilitates PLS3 phosphorylation, PKC-δ/PLS3 interaction, and CL translocation, which consequently promote apoptosis. In contrast, heat shock protein 27 (Hsp27) blocks PKC-δ-induced PLS3 phosphorylation, suppresses PKC-δ/PLS3 interaction and CL translocation, and inhibits apoptosis. Conclusions: Our findings suggest that phosphorylation of PLS3 by PKC-δ is involved in the hyperthermia-induced apoptotic signal transduction pathway in Tca8113 cells, and that Hsp27 blocks this pathway to suppress hyperthermia-induced apoptosis.