Effect of electroacupuncture preconditioning on expression of cortical Ubc9 during cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of electroacupuncture (EA) preconditioning on expression of cortical Ubc9 during cerebral ischemia-reperfusion (I/R) in rats.Methods:A total of 80 healthy clean-grade male Sprague-Dawley rats, aged 8-12 weeks, weighing 200-250 g, were divided into 4 groups ( n=20 each) using a random number table method: sham operation group (group S), group I/R, EA preconditioning group (group E) and sham EA group (group SE). Blood vessels were only exposed, without occlusion in group S. In the other three groups, the cerebral I/R model was established by middle cerebral artery occlusion using suture-occluded method, and the suture was removed after 2-h occlusion to restore the perfusion in anesthetized rats.EA was performed at 5 days before establishing the model in group E and group SE.Baihui acupoints were stimulated with an electric stimulator (2/12 Hz disperse-dense waves, intensity 1 mA) for 30 min once a day for 5 consecutive days, and the model was established at 24 h after the last stimulation.EA was performed at the points 1 cm lateral to the acupoints of Baihui, and the other operating parameters were the same as those previously described in group E. Neurological deficit scores (NDSs) were evaluated at 24 and 48 h of reperfusion.Then the rats were sacrificed, and tissues in the ischemic penumbra of cerebral cortex were obtained for determination of cell apoptosis (by TUNEL) and expression of Ubc9 and conjugated small ubiquitin-like modifier (SUMO) 2/3 (by Western blot). The apoptosis rate was calculated. Results:Compared with group S, NDSs at 24 and 48 h of reperfusion and apoptosis rate were significantly increased, and the expression of Ubc9 and conjugated SUMO2/3 was up-regulated in the other three groups ( P<0.05). Compared with group I/R and group SE, NDSs at 24 and 48 h of reperfusion and apoptosis rate were significantly decreased, and the expression of Ubc9 and conjugated SUMO2/3 was up-regulated in group E( P<0.05). Conclusion:The mechanism by which EA preconditioning reduces cerebral I/R injury is related to up-regulating Ubc9 expression and thus enhancing SUMO2/3ylation in rats.