Journal of Capital Medical University ›› 2021, Vol. 42 ›› Issue (2): 232-238.doi: 10.3969/j.issn.1006-7795.2021.02.012

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

Effects of mitochondrial reactive oxygen species inhibitor R(+)-pramipexole on JAK2-STAT3 signaling pathway and pro-inflammatory factor TNF-α in rats with cerebral ischemia/reperfusion injury

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

  1. Xuanwu Hospital, Capital Medical University, Beijing Geriatric Medical Research Center, Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing 100053, China
  • Received:2021-01-14 Published:2021-04-26
  • Contact: *E-mail:kliu@salud.unm.edu

Abstract: Objective To study the effect of mitochondrial reactive oxygen species (ROS) inhibitor R(+)-pramipexole [R(+)-PPX] on the janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) signaling pathway and pro-inflammatory factor tumor necrosis factor-α (TNF-α) in middle cerebral artery occlusion (MCAO) rats after 6 h reperfusion, and further to investigate the protective mechanism of R(+)-PPX on cerebral ischemia injury at early stage of reperfusion.Methods Thirty healthy male Sprague-Dawley rats were divided into Sham group, MCAO group, and R(+)-PPX group (n=10), according to random number table. MCAO rat model was established with modified suture method, the rats underwent 90 min of right MCAO and then reperfusion by withdrawing the filament. The anus temperature of the rats was monitored during the operation. The rats were sacrificed after 6h reperfusion, and then the brain was collected quickly. The level of p-JAK2 protein in ischemic brain tissue was determined with Western blotting. The expressions of p-STAT3 and TNF-α in the ischemic penumbra of frozen sections of brain tissues were detected with immunofluorescence staining. The ROS positive cells in the ischemic penumbra was detected with dihydroethidium (DHE) staining. Colocalization of ROS with p-STAT3 or TNF-α was examined with double labeling immunofluorescence staining in the ischemic penumbra. Colocalization of p-STAT3 and TNF-α was analyzed with double labeling immunofluorescence staining. Results 1) Compared with Sham group, the level of p-JAK2 protein was upregulated obviously in ischemic brain tissue of MCAO rats after 6 h reperfusion (P<0.05). The level of p-JAK2 protein decreased significantly in the ischemic brain tissue of R(+)-PPX group compared with that of MCAO group (P<0.05). 2) No p-STAT3 positive cell was observed in Sham group. The p-STAT3 positive cells in the ischemic penumbra of MCAO group increased obviously after 6 h reperfusion compared with Sham group (P<0.05). The p-STAT3 positive cells decreased significantly in the ischemic penumbra of R(+)-PPX group compared with MCAO group (P<0.05). ROS was colocalized with p-STAT3 in the ischemic penumbra of rats. 3) No TNF-α positive cell was observed in Sham group. The TNF-α positive cells in the ischemic penumbra of MCAO group increased obviously after 6 h reperfusion compared with Sham group (P<0.05). The TNF-α positive cells decreased significantly in the ischemic penumbra of R(+)-PPX group compared with MCAO group (P<0.05). ROS was colocalized with TNF-α in the ischemic penumbra of rats. 4) p-STAT3 was colocalized with TNF-α with immunofluorescence staining in the ischemic penumbra of MCAO group after 6 h reperfusion. Conclusion The mitochondrial ROS inhibitor R(+)-PPX may play a neuroprotective role at early stage of cerebral ischemia/reperfusion injury via inhibiting the activation of the JAK2-STAT3 signaling pathway and reducing the level of TNF-α in ischemic brain tissue of MCAO rats after 6 h reperfusion.

Key words: cerebral ischemia/reperfusion, mitochondrial reactive oxygen species, R(+)-PPX, janus kinase 2-signal transducer and activator of transcription 3 signaling pathway, tumor necrosis factor-α

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