ATG5 and ATG7 induced autophagy interplays with UPR via PERK signaling
ATG5 and ATG7 induced autophagy interplays with UPR via PERK signaling
复制标题
ATG5 和 ATG7 通过 PERK 信号传导诱导自噬与 UPR 相互作用。
DOI：
10.1186/s12964-019-0353-3
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发表时间：
2019-05-06
影响因子：
8.4
通讯作者：
Guo, Fengjin
中科院分区：
文献类型：
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作者：
Zheng, Wei;Xie, Weiwei;Guo, Fengjin
背景自噬和内质网应激参与维持细胞内环境的稳定或导致细胞死亡。自噬是一个定义明确的过程，它控制着整个细胞应激结果。自噬介导的ER的选择性降解发生通过一种特定类型的自噬称为ER-吞噬，这确保ER蛋白homeostasis.MethodsImmunoblotting和RT-PCR被用来评估软骨细胞中的ATG 5和ATG 7的表达。采用Western blotting、流式细胞术、免疫荧光细胞染色和共聚焦显微镜观察ATG 5和ATG 7对细胞自噬、内质网应激、细胞凋亡和细胞增殖的影响。透射电子显微镜和共聚焦显微镜观察自噬流和自溶体的形成。免疫印迹和治疗inhibitors.ResultsIn目前的研究中，我们表明，TM诱导的ER应激可以激活自噬，而雷帕霉素诱导的自噬可以抑制ER应激软骨细胞中的PERK通路抑制剂的作用，检测ATG 5和ATG 7过表达。自噬相关蛋白ATG 5或ATG 7单独作用可促进自噬和抑制内质网应激，二者联合作用可进一步增强自噬的增强和内质网应激的抑制。ATG 5、ATG 7及ATG 5 + ATG 7均能诱导细胞进入更多的S期，增加S期细胞的数目，抑制细胞凋亡。ATG 5、ATG 7和ATG 5 + ATG 7通过PERK分支通路调节自噬、内质网应激、细胞凋亡和细胞周期。ATG 5/7过表达对软骨细胞存活的保护作用依赖于PERK信号传导。siPERK和siNrf 2对ATG 5/7的细胞保护作用具有协同作用，而siPERK和siATF 4对ATG 5/7的细胞保护作用具有拮抗作用。PERK信号可能是软骨细胞自噬、ER稳态和ER吞噬的中枢。
BackgroundAutophagy and ER stress are involved in maintaining some well-orchestrated mechanisms aimed at either restoring cellular homeostasis or performing cell death. Autophagy is a well-defined process which governs overall cellular stress outcomes. Selective degradation of the ER mediated by autophagy occurs through a specific type of autophagy called ER-phagy, which ensures ER protein homeostasis.MethodsImmunoblotting and RT-PCR were used to evaluate the expression of ATG5 and ATG7 in chondrocyte. Western blotting, Flow cytometry,immunofluorescence cell staining and confocal microscope were used to examine the effect of ATG5 and ATG7 on autophagy, ER stress, cell apoptosis and cell proliferation. Transmission electron microscope and confocal microscope were performed to visualize the autophagy flux and autolysosome formation. The role of ATG5 and ATG7 overexpression on the PERK pathway inhibitor were detected by immunoblotting and treatment with inhibitors.ResultsIn current study, we demonstrated that Tm-induced ER stress can activate autophagy while Rapamycin-induced autophagy can inhibit ER stress in chondrocyte. Autophagy related protein ATG5 or ATG7 can promote autophagy and inhibit ER stress individually, and their combined effect can further improve the autophagy enhancement and the ER stress repression. Moreover, ATG5, ATG7 and ATG5+ATG7 lead cells into more S phase, increase the number of S phase and inhibit apoptosis as well. ATG5, ATG7 and ATG5+ATG7 regulate autophagy, ER stress, apoptosis and cell cycle through PERK signaling, a vital UPR branch pathway.ConclusionsATG5 and ATG7 connect autophagy with ER stress through PERK signaling. The protective effect of ATG5/7 overexpression on chondrocyte survival relys on PERK signaling. The effect of siPERK and siNrf2 on the cytoprotective effect of ATG5/7 are of synergism, while the effect of siPERK and siATF4 are of antagonism. PERK signal may be the pivot for autophagy, ER homeostasis and ER-phagy in chondrocyte.