Urolithin A-activated autophagy but not mitophagy protects against ischemic neuronal injury by inhibiting ER stress in vitro and in vivo
Urolithin A-activated autophagy but not mitophagy protects against ischemic neuronal injury by inhibiting ER stress in vitro and in vivo
复制标题
尿石素 A 激活的自噬（而非线粒体自噬）通过抑制体外和体内 ER 应激来防止缺血性神经元损伤
DOI：
10.1111/cns.13136
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发表时间：
2019-09-01
影响因子：
5.5
通讯作者：
Chen, Zhong
中科院分区：
文献类型：
--
作者：
Ahsan, Anil;Zheng, Yan-Rong;Chen, Zhong
目的线粒体自噬（mitochondrialautophagy，mitophagy）清除受损的线粒体，减轻缺血性神经元损伤。尿石素A（Uro-A）激活哺乳动物细胞和秀丽隐杆线虫中的线粒体自噬。我们探讨了Uro-A对缺血性神经元损伤的神经保护作用。方法采用小鼠大脑中动脉闭塞模型。测量脑梗死和神经功能缺损评分。采用缺氧缺糖再灌注（OGD/R）法对N2 a细胞和原代培养的小鼠皮层神经元进行缺氧缺糖再灌注（OGD/R）。在OGD/R过程中孵育Uro-A，MTT法和LDH法检测Uro-A对细胞的损伤。通过检测mCherry微管相关蛋白1轻链3（LC 3）来观察自噬体。Western blot检测LC 3-II、p62、线粒体内膜转位酶23（TIMM 23）和细胞色素c氧化酶亚基4亚型1（COX 4 I1）蛋白水平。逆转录-聚合酶链反应（RT-PCR）检测ER应激标志物转录激活因子6（ATF 6）和C/EBP同源蛋白（CHOP）。结果尿石素A可减轻OGD/R诱导的N2 a细胞和神经元损伤，减轻小鼠缺血性脑损伤。Uro-A增强缺血诱导的自噬。此外，Uro-A赋予的保护作用被3-甲基腺嘌呤消除，表明神经保护需要自噬。然而，线粒体自噬没有被Uro-A进一步激活。相反，Uro-A减弱OGD/R诱导的ER应激，这被3-甲基腺苷消除。此外，ER应激诱导剂可逆转神经保护作用。结论尿石素A对缺血性神经元损伤的保护作用可能是通过增强自噬而非线粒体自噬。Uro-A激活自噬通过抑制内质网应激减轻缺血性神经元死亡。
Aim Mitochondrial autophagy (mitophagy) clears damaged mitochondria and attenuates ischemic neuronal injury. Urolithin A (Uro-A) activates mitophagy in mammal cells and Caenorhabditis elegans. We explored neuroprotection of Uro-A against ischemic neuronal injury. Methods Mice were subjected to middle cerebral artery occlusion. The brain infarct and neurological deficit scores were measured. The N2a cells and primary cultured mice cortical neurons were subjected to oxygen-glucose deprivation and reperfusion (OGD/R). Uro-A was incubated during OGD/R, and cell injury was determined by MTT and LDH. Autophagosomes were visualized by transfecting mCherry-microtubule-associated protein 1 light chain 3 (LC3). The protein levels of LC3-II, p62, Translocase Of Inner Mitochondrial Membrane 23 (TIMM23), and cytochrome c oxidase subunit 4 isoform 1 (COX4I1) were detected by Western blot. The ER stress markers, activating transcription factor 6 (ATF6) and C/EBP homologous protein (CHOP), were determined by reverse transcription-polymerase chain reaction (RT-PCR). Results Urolithin A alleviated OGD/R-induced injury in N2a cells and neurons and reduced ischemic brain injury in mice. Uro-A reinforced ischemia-induced autophagy. Furthermore, Uro-A-conferred protection was abolished by 3-methyladenine, suggesting the requirement of autophagy for neuroprotection. However, mitophagy was not further activated by Uro-A. Instead, Uro-A attenuated OGD/R-induced ER stress, which was abolished by 3-methyladenosine. Additionally, neuroprotection was reversed by ER stress inducer. Conclusion Urolithin A protected against ischemic neuronal injury by reinforcing autophagy rather than mitophagy. Autophagy activation by Uro-A attenuated ischemic neuronal death by suppressing ER stress.