Regulatory effects of electroacupuncture pretreatment on microRNA-223 in the hippocampus of mice with global cerebral ischemia injury

Abstract

Objective To investigate whether electroacupuncture(EA) pretreatment affects the expression of microRNA-223 (miR-223) in the hippocampus of mice with global cerebral ischemia (GCI) injury. Methods A total of twenty-five adult male C57/BL mice were randomly divided into three groups according to the random numbers table method: Sham group(n=5), GCI group (n=15), EA pretreatment group(EA+GCI group, n=5). In the sham group, a ventral midline incision was made to expose the trachea without any other procedures. Mice in GCI group were subjected to global cerebral ischemia, animals were sacrificed and the hippocampus was dissected at 12, 24, 36 h after reperfusion, respectively. In the EA+GCI group, mice were given EA pretreatment at Baihui acupoint for 2 h before GCI. The miR-223 expression in the hippocampus was assayed with real-time fluorescence quantitative PCR(real-time fqPCR) after GCI-reperfusion injury. Neurobehavioral evaluation and Nissl staining were used to analyze the neuroprotection by EA pretreatment. Results Compared with the Sham group, there was a marked increase in miR-223 expression in the pyramidal neurons 24 h after reperfusion(P<0.05). EA pretreatment significantly blocked the up-regulation of miR-223 and improved the neurological scores compared with GCI group (P<0.05). There was also a significant increase in the viability of CA1 pyramidal neurons in EA+GCI group, compared with that of the GCI group(P<0.05). Conclusions EA preconditioning improves cerebral ischemia tolerance after GCI via suppressing the up-regulation of miR-223. Key words: MicroRNA; Global cerebral ischemia; Electroacupuncture; Pretreatment