Effect of wheat-grain moxibustion on the expression of Beclin-1/GRP78 in spinal dorsal horn in rats with cervical spondylotic radiculopathy

Abstract

To observe the effect of wheat-grain moxibustion at "Dazhui" (GV 14) on the expressions of Beclin-1 and GRP78 in spinal dorsal horn in rats with cervical spondylotic radiculopathy (CSR), and to explore the possible analgesic mechanism of wheat-grain moxibustion for CSR. A total of 48 SD rats were randomly divided into a sham operation group, a model group, a wheat-grain moxibustion group and a wheat-grain moxibustion+3-MA group, 12 rats in each group. The CSR model was prepared by spinal cord insertion method. Three days after modeling, the rats in the model group were intraperitoneally injected with 1 mL of 0.9% sodium chloride solution; the rats in the wheat-grain moxibustion group were treated with wheat-grain moxibustion at "Dazhui" (GV 14, 6 cones per time) on the basis of the model group; the rats in the wheat-grain moxibustion+3-MA group were intraperitoneally injected with 3-MA solution and wheat-grain moxibustion at "Dazhui" (GV 14, 6 cones per time). The three groups were intervened for 7 days, once a day. The gait score and mechanical pain threshold were observed before treatment and 7 days into treatment; after the treatment, the expressions of mRNA and protein of Beclin-1 in spinal dorsal horn were detected by real-time fluorescence quantitative PCR and immunohistochemistry; the expression of GRP78 protein in spinal dorsal horn was detected by Western blot method; the autophagosomes and ultrastructure in spinal dorsal horn neurons were observed by electron microscope. After the treatment, compared with the sham operation group, in the model group, the gait score was increased and the mechanical pain threshold was decreased (P<0.01), and the expression of GRP78 protein in spinal dorsal horn was increased (P<0.01). Compared with the model group and the wheat-grain moxibustion+3-MA group, in the wheat-grain moxibustion group, the gait score was decreased and mechanical pain threshold was increased (P<0.01), and the expression of GRP78 protein in spinal dorsal horn was decreased, and the expressions of mRNA and protein of Beclin-1 were increased (P<0.01). Under electron microscope, the ultrastructure of spinal dorsal horn neurons in the wheat-grain moxibustion group was not significantly damaged, and its structure was basically close to normal, and the number of autophagosomes was more than the other three groups. Wheat-grain moxibustion at "Dazhui" (GV 14) has analgesic effect on CSR rats. The mechanism may be related to moderately up-regulate the expression of Beclin-1, enhance autophagy and reduce endoplasmic reticulum stress.