Journal of Capital Medical University ›› 2021, Vol. 42 ›› Issue (2): 225-231.doi: 10.3969/j.issn.1006-7795.2021.02.011

• Basic Research on Cerebral lschemic Injury • Previous Articles     Next Articles

Effect of remote ischemic preconditioning on PERK/p-eIF2α pathway and autophagy in the penumbra of rats with focal cerebral ischemia/reperfusion injury

Yang Nan, Ding Mao, Yan Feng, Shi Wenjuan, Huang Yuyou, Zhao Yongmei*   

  1. Central Laboratory, Xuanwu Hospital, Capital Medical University, Beijing Geriatric Medical Research Center, Key Laboratory of Neurodegenerative Diseases of Ministry of Education, Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing 100053, China
  • Received:2021-01-14 Published:2021-04-26
  • Contact: *E-mail:yongmeizhao@hotmail.com

Abstract: Objective To investigate the protective effect and mechanism of remote ischemic preconditioning (RIPC) on cerebral ischemia injury via studying the expressions of autophagy-related protein Beclin1, LC3B and chaperone of endoplasmic reticulum GRP78, as well as endoplasmic reticulum stress (ERS)-related pathway PERK/p-eIF2α in the penumbra of rats with focal cerebral ischemia/reperfusion.Methods A total of 24 male Sprague Dawley rats were divided randomly into 3 groups: Sham group, middle cerebral artery occlusion (MCAO) group and RIPC+MCAO group, with n=8 for each group. A model of MCAO was induced with the intraluminal suture method. The rats underwent 90 minutes of MCAO and then were reperfused for 24 h by withdrawal of the filament. Three cycles of RIPC had been given three times a day for 3 days before the MCAO surgery, induced by temporarily occluding the bilateral femoral arteries (10 minutes) prior to 10 minutes of reperfusion. The positive expressions of autophagy-related protein Beclin1 and LC3B, as well as GRP78 and p-eIF2α in the ischemic penumbra of the brain tissues sections were detected with immunofluorescence double staining. Results 1) There was little Beclin1 positive cells in the Sham group. Compared with Sham group, the Beclin1 positive cells in the penumbra of MCAO group obviously increased after 24 h reperfusion (P<0.05). Compared with MCAO group, the Beclin1 positive cells decreased significantly in the penumbra of RIPC+MCAO group. The Beclin1 positive cells were colocalized with NeuN, a general neuronal marker, in the brain ischemic penumbra. 2)In the penumbra of MCAO group rats after 24 h reperfusion, GRP78 was colocalized with Beclin1 and LC3B,respectively, which was examined with immunofluorescence staining. 3)In the penumbra of brain tissue of MCAO group with 24 h reperfusion, Beclin1 was colocalized with p-eIF2α. No Beclin1 and p-eIF2α double positive cell was observed in the Sham group. Lots of Beclin1 and p-eIF2α double positive cells were observed in the ischemic penumbra of MCAO group after 24 h reperfusion. After treated with RIPC, the Beclin1 and p-eIF2α double positive cells in the penumbra of the ischemia rats were significantly decreased compared with that in MCAO group (P<0.05). Conclusion RIPC may inhibit endoplasmic reticulum stress (ERS)-related pathway PERK/eIF2α and reduce the expression of autophagy-related protein, alleviate excessive activation of neuronal autophagy, and thus exerts neuroprotective effects on cerebral ischemia/reperfusion injury.

Key words: cerebral ischemia/reperfusion, autophagy, Beclin1, PERK/p-eIF2α, endoplasmic reticulum stress

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