Endoplasmic reticulum chaperone GRP78 is involved in autophagy activation induced by ischemic preconditioning in neural cells.
Endoplasmic reticulum chaperone GRP78 is involved in autophagy activation induced by ischemic preconditioning in neural cells.
复制标题
内质网伴侣GRP78参与神经细胞缺血预处理诱导的自噬激活
DOI：
10.1186/s13041-015-0112-3
复制
发表时间：
2015-03-26
期刊：
影响因子：
3.6
通讯作者：
Sheng R
中科院分区：
文献类型：
--
作者：
Zhang XY;Zhang TT;Song DD;Zhou J;Han R;Qin ZH;Sheng R
背景我们的前期研究表明脑缺血预处理通过内质网应激诱导的自噬介导神经保护作用。本研究旨在探讨内质网伴侣蛋白GRP 78在缺血预适应（IPC）诱导的神经细胞自噬激活中的作用。结果在大鼠嗜铬细胞瘤（PC 12）细胞和原代培养的小鼠皮层神经元中建立了缺血预适应（IPC）和氧葡萄糖剥夺（OGD）模型。IPC对PC 12细胞和原代皮层神经元随后的OGD损伤具有神经保护作用。IPC增加GRP 78表达并激活自噬，如通过上调LC 3和Beclin 1所证明的，增加自噬通量和自噬体的形成。BAPTA（dibromo-1，2-bis（aminophenoxy）ethane N，N，N9，N9 -tetraacetic acid，0.125-2 μM）和小干扰RNA靶向GRP 78可阻断IPC诱导的神经保护作用，并降低GRP 78、LC 3 II/LC 3 I和Beclin 1的表达。相比之下，慢病毒载体介导的GRP 78过表达（LV-GRP 78）增强了PC 12细胞对OGD损伤的抵抗力，并增加了LC 3和Beclin 1的表达。此外，在稳定的GRP 78过表达的PC 12细胞中敲低GRP 78消除了LC 3 II/LC 3 I的上调。GRP 78可能通过AMPK-mTOR途径激活自噬。结论IPC诱导的GRP 78上调参与了自噬激活，从而对神经细胞缺血损伤具有保护作用。
BackgroundOur previous finding showed that brain ischemic preconditioning mediates neuroprotection through endoplasmic reticulum (ER) stress-induced autophagy. This study was aimed at exploring the role of ER chaperone GRP78 in IPC induced autophagy activation in neural cells.ResultsIschemic preconditioning (IPC) and oxygen glucose deprivation (OGD) models were established in rat pheochromocytoma (PC12) cells and primary cultured murine cortical neurons. IPC exerted neuroprotection against subsequent OGD injury in both PC12 cells and primary cortical neurons. IPC increased GRP78 expression and activated autophagy, as evidenced by upregulated LC3 and Beclin1, increased autophagic flux and formation of autophagosomes. BAPTA(dibromo-1,2-bis(aminophenoxy)ethane N,N,N9,N9 - tetra acetic acid, 0.125-2 μM) and small interfering RNA targeted GRP78 abrogated IPC induced neuroprotection and decreased the expression of GRP78, LC3II/LC3I and Beclin1. In contrast, lentiviral vector mediated GRP78 overexpression (LV-GRP78) strengthened resistance of PC12 cells to OGD injury and increased LC3 and Beclin1 expression. Moreover, knockdown of GRP78 in stable GRP78 overexpressing PC12 cells abolished the upregulation of LC3II/LC3I. GRP78 might activate autophagy through AMPK - mTOR pathway.ConclusionThese results suggest that IPC- induced GRP78 upregulation is involved in autophagy activation, and hence exerts protection against ischemic injury in neural cells.