Effect of electroacupuncture of Governor Vessel on mitochondrial fusion and proliferation and differentiation of neural stem cells in spinal cord injury rats.

OBJECTIVES

To observe the effect of electroacupuncture (EA) at "Dazhui" (GV14) and "Jizhong"(GV6) of the Governor Vessel (GV) on mitochondrial fusion and neural stem cell (NSC) proliferation and differentiation in the spinal cord of rats with spinal cord injury (SCI), so as to investigate its mechanisms underlying improvement of SCI.

METHODS

SD rats were randomly divided into sham operation, model and EA groups, with 15 rats in each group. The SCI model was established by using a precision impactor. EA (20 Hz/100 Hz, 1-2 mA) was applied to GV14 and GV6 for 30 min, once daily for 14 days. The rats' hindlimb locomotor function in each group was assessed using the Basso-Beattie-Bresnahan (BBB) locomotor scale. Histopathological changes of the injured spinal cord tissue and the number of neurons were evaluated after H.E. staining and Nissl staining. The expressions of Nestin, mitochondrial fusion-related protein optic atrophy-1 (OPA1) and NSC markers sex-determining region Y-box 2 (SOX2) in the injured spinal cord tissue were detected by immunofluorescence staining. The protein and mRNA expression levels of Nestin in the spinal cord tissue were detected by quantitative real-time PCR and Western blot, separately.

RESULTS

Compared with the sham operation group, the BBB scores after modeling, and the number of neurons were significantly decreased (0.001), while the mean fluorescence intensity values of Nestin, SOX2 and OPA1, and the expressions of Nestin mRNA and protein considerably increased (0.001, 0.01, 0.05) in the model group. After EA intervention and in comparison with the model group, the BBB scores at the 7 and 14 day, the number of neurons, the mean fluorescence intensity values of Nestin, SOX2 and OPA1, and the expressions of Nestin mRNA and protein were strikingly increased (0.05, 0.01, 0.001) in the EA group. H.E. staining showed swollen, ruptured and necrotic neurons of the spinal cord, with a large number of vacuoles and severe inflammatory cell infiltration after modeling, which was relatively milder in the EA group.

CONCLUSIONS

EA stimulation of GV14 and GV6 can promote the recovery of motor function in rats with SCI, which may be related to its effects in promoting mitochondrial fusion and enhancing the proliferation and differentiation of NSCs.