Inhibition of autophagy promotes caspase-mediated apoptosis by tunicamycin in HepG2 cells
Inhibition of autophagy promotes caspase-mediated apoptosis by tunicamycin in HepG2 cells
复制标题
衣霉素抑制自噬促进 HepG2 细胞中 caspase 介导的细胞凋亡
DOI：
10.3109/15376516.2014.956915
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发表时间：
2014-08
期刊：
影响因子：
--
通讯作者：
Xiao X
中科院分区：
文献类型：
--
作者：
Zhang S;Wang C;Tang S;Deng S;Zhou Y;Dai C;Yang X;Xiao X
衣霉素（TM）引起内质网腔内未折叠蛋白的积累，并从其他方面引入内质网应激。本研究旨在探讨TM诱导HepG 2细胞凋亡和自噬的作用以及自噬在该系统中的作用。MTT法检测TM对HepG 2细胞活力的抑制作用，并呈剂量依赖性。凋亡细胞形态学改变、凋亡细胞率增加提示TM可诱导细胞凋亡，且呈时间和剂量依赖性。进一步研究TM诱导的细胞凋亡中caspase-3/7、8、9的活性及PARP的裂解，发现TM处理后caspase-9和pan caspase抑制剂能有效抑制TM诱导的细胞凋亡。此外，提供了上升的染色酸性空泡和增加的LC 3 II水平和Beclin 1的激活，我们得出结论，自噬可以被TM以时间和剂量依赖性的方式触发。此外，自噬的抑制有效地促进TM诱导的细胞死亡通过MTT法鉴定。同时，自噬阻断后凋亡细胞率和caspase-3活性显著增加。总之，我们发现TM在HepG 2细胞中以时间和剂量依赖的方式启动凋亡和自噬;抑制自噬可能通过增强凋亡促进TM诱导的细胞死亡。
Abstract Tunicamycin (TM) causes accumulation of unfolded protein in endoplasmic reticulum (ER) lumen and introduces from elsewhere ER stress. This study was to assess the apoptosis and autophagy effect induced by TM on HepG2 cells and the role of autophagy in the system. The viability of HepG2 cells was significantly inhibited by TM in a dose-dependent manner detected by MTT assay. Then, the apoptotic morphology change, increasing apoptotic cell rate suggested that apoptosis was induced by TM in a time- and dose-dependent manner. To further determine the involvement of caspase-dependent pathway in TM-induced apoptosis, we discover that the activity of caspase-3/7, 8, 9 and cleavage of PARP markedly increased after TM treatment and the apoptosis was effectively attenuated by using caspase-9 and pan caspase inhibitor. Moreover, provided the rising stained acidic vacuoles and an increased level of LC3II and activation of Beclin1, we concluded that autophagy could be triggered by TM in a time- and dose-dependent manner. In addition, the inhibition of autophagy efficiently promoted TM-induced cell death identified by MTT assay. Meanwhile, the apoptotic cell rate and caspase-3 activation increased significantly after autophagy blockage. In conclusion, we found that TM initiated apoptosis and autophagy both in a time- and dose-dependent manner in HepG2 cells; and inhibition of autophagy may promote TM-induced cell death through enhancing apoptosis.
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影响因子：
11.1
作者：
He C;Klionsky DJ
通讯作者：
Klionsky DJ
影响因子：
11.2
作者：
Fels DR;Ye J;Segan AT;Kridel SJ;Spiotto M;Olson M;Koong AC;Koumenis C
通讯作者：
Koumenis C
影响因子：
21.3
作者：
Tabas, Ira;Ron, David
通讯作者：
Ron, David
DOI：
10.1073/pnas.92.16.7162
发表时间：
1995-08-01
影响因子：
11.1
作者：
BONFOCO, E;KRAINC, D;LIPTON, SA
通讯作者：
LIPTON, SA
影响因子：
4.8
作者：
Morishima, N;Nakanishi, K;Yasuhiko, Y
通讯作者：
Yasuhiko, Y