Effect of eye acupuncture on autophagy in brain tissue of rats with cerebral ischemia-reperfusion injury

Abstract

to observe the effect of eye acupuncture on cerebral blood flow and autophagy of cerebral tissue in rats with cerebral ischemia-reperfusion injury, so as to explore the mechanism of eye acupuncture underlying improvement of cerebral ischemia-reperfusion injury. Fifty SD rats were randomly divided into sham operation, model, eye acupuncture, inhibitor and enhancer groups，with 10 rats in each group. The rat model of cerebral ischemia-reperfusion injury was established by occlusion of the middle cerebral artery for 1.5 h. The rats in the eye acupuncture group were treated with eye acupuncture for 30 minutes immediately, 12 h and 24 h after the modeling. Rats in the inhibitor group and enhancer group were given intracerebroventricular injection of autophagy agonist 3-Methyladenine or autophagy inducer Rapamycin 30 min before modeling. Longa's scoring method was used to evaluate the neurological function. The blood flow velocity of the cerebral cortex was mea-sured with a laser doppler blood flow meter, and the neuron damage in the brain tissue was observed with Nissl staining. The expressions of autophagy-related protein Beclin-1, microtubule-associated protein 1 light chain 3 (LC3), and p62 were measured by Western blot. Compared with the sham operation group, the neurological score of the model group was significantly increased (P<0.01); the blood flow volume and blood flow speed were significantly reduced (P<0.01); the number of Nissl bodies in the ischemic brain tissue decreased (P<0.01); Beclin-1 protein expression level and LC3-II/LC3-I increased, while p62 expression level decreased(P<0.01). After intervention and in comparison with the model group, the neurological scores in the eye acupuncture group and inhibitor group decreased (P<0.01); blood flow volumn and blood flow speed significantly increased (P<0.01); the number of Nissl bodies increased (P<0.01); the expression level of Beclin-1 protein and LC3-II/LC3-I decreased, and the expression level of p62 increased (P<0.01). There was no significant difference between the enhancer and the model groups in the abovementioned indexes(P>0.05). Eye acupuncture can improve the neurological function of rats with cerebral ischemia-reperfusion injury, which may be related to accelerating cerebral blood flow and inhibiting autophagy in the ischemic brain.