Effects of Tangeretin on Neuronal Pyroptosis in Rats with Cerebral Ischemia/Reperfusion Injury Through PI3K/Akt Signaling Pathway-Mediated Autophagy
OBJECTIVE To investigate the effect of tangeretin(TAN)on neuronal pyroptosis in rats with cerebral ischemia/reperfusion injury(CIRI)and its mechanism.METHODS The CIRI model of rats was established by reperfusion after occlusion of the middle cerebral artery for 2 h using thread occlusion method.Experiment 1:SD rats were randomly divided into sham group,CIRI group,TAN-5 mg·kg-1,TAN-10 mg·kg-1,TAN-20 mg·kg-1,and positive control edaravone group(EDA-10 mg·kg-1),with 10 rats in each group.The rats in each group were subjected to index detection and pathological sampling 24 hours after reperfusion.Zea Longa method was used to score neurological deficits;the rate of cerebral infarction was detected using the 2,3,5-triphenyl tetrazo-lium chloride(TTC)method;hematoxylin eosin(HE)staining was used to observe the morphology and structure of brain tissue,and the optimal dosage of TAN was selected;propidium iodide staining(PI)was used to detect the ratio of neuronal focal death;immuno-fluorescence double staining was used to detect the positive expression rate of LC3-Ⅱ in neurons;Western blot was performed for de-tection of the expressions of pyroptosis-related proteins,PI3K/Akt pathway-related proteins,and autophagy-related proteins(LC3-Ⅱ/LC3-Ⅰ,p62)in brain tissue.Experiment 2:SD rats were randomly divided into sham group,CIRI group,TAN group,and TAN+PI3K inhibitor group(LY294002),with 10 rats in each group.After 24 hours of reperfusion,indicators were tested and pathological samples were taken from each group of rats.Zea Longa method was used to score neurological deficits;TTC staining was used to detect the rate of cerebral infarction;Western blot was used to detect the expressions of pyroptosis-related proteins and autophagy-related pro-teins in brain tissue.RESULTS Compared with the CIRI group,the neurological deficit score,cerebral infarction volume ratio,and pathological damage to brain tissue of rats in each dose group were reduced.The TAN-20 mg·kg-1 was selected as the optimal dose group.Compared with the CIRI group,the rate of pyroptosis of neurons was reduced,and the expressions of pyroptosis-related proteins were downregulated,and the positive cell rate of neuron LC3-Ⅱ and the expression of LC3-Ⅱ/LC3-Ⅰ were reduced,the expressions of p-PI3K/PI3K,p-Akt/Akt,and p62 were increased in TAN-20 mg·kg-1 group.Compared with the TAN-20 mg·kg-1 group,the PI3K inhibitor LY294002 inhibited the changes in the above indicators and reverse the neuroprotective effect of TAN on CIRI rats.CONCLUSION TAN can inhibit neuronal pyroptosis via regulating PI3K/Akt-mediated autophagy induced by cerebral ischemia-reperfusion.
万方数据
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