Effects of electroacupuncture on neurological function and expressions of p-JNK and Beclin-1 in traumatic brain injury rats

Abstract

To observe the effect of electroacupuncture (EA) on neurological function, the expressions of phosphorylated c-Jun amino terminal kinase (p-JNK) and Beclin-1 in rats with traumatic brain injury (TBI), so as to explore the underlying mechanism of EA in the treatment of TBI. A total of 64 SD rats were randomly divided into blank, sham, modeling groups, with 8 rats in the blank group and the sham group and 48 rats in the modeling group. The modified Feeney free-fall impact method was used to establish the TBI rat model. After modeling, rats of the modeling group were randomly divided into model and EA groups, which were further divided into 3 d, 7 d and 14 d subgroups with 8 rats in each group. Rats in the EA group were treated with acupuncture at "Baihui" (GV20, retained for 15 min), "Shuigou" (GV26, stabbed for 20 s), "Neiguan" (PC6) and "Zusanli" (ST36) of the right side. EA (2 Hz, 1 mA) was applied to PC6 and ST36 for 15 min. The above treatments were performed once a day, and different subgroups were continuously stimulated for 3, 7 and 14 days, respectively. The neurological impairment was evaluated by modified neurological severity score(mNSS). The pathological morphological changes and the protein expressions of p-JNK and Beclin-1 in the injured area of the brain were detected by Nissl staining and immunohistochemistry, separately. After modeling, the mNSS and the protein expressions of p-JNK and Beclin-1 were increased (P< 0.05) on day 3, 7 and 14 in the model group relative to the sham group. The Nissl bodies were reduced or even dissolved and neurons were seriously damaged in the model group on the 3rd day, which were mildly repaired on day 7 and 14. Following acupuncture interventions, compared with the model group, the mNSS on day 7 and 14 and the protein expressions of p-JNK and Beclin-1 on day 3, 7 and 14 were decreased (P< 0.05)in the EA group. The status of Nissl bodies and neurons in the EA group was better at all time points than that in the model group. There were no significant differences in the above indicators between the blank group and the sham group. EA can significantly improve the neurological function of TBI model rats, which may be related to its effects in down-regulating the protein expressions of p-JNK and Beclin-1 in the injured area of the brain.