| Objective: To observe the effect of electroacupuncture(EA)intervention at the Jiaji points(EX-B2)on the recovery of motor function in the hind limbs of rats with spinal cord injury,as well as the effect on the Notch signaling pathway and GFAP expression,so as to explore the protective mechanism of EA at EX-B2 against spinal cord injury.Methods: A total of 72 male SD rats(250±20)g were divided into four groups according to the random number table method,namely,sham operation group,spinal cord injury group,electroacupuncture group,and acupuncture group,with 18 rats in each group.The thoracic 10-segment spinal cord injury model was prepared by the modified Allen’s method,and a BBB score of 0 represented successful modeling,in which the shamoperated group only pried open the vertebral plate without damaging the spinal cord.Before the intervention,the rats were fixed in a prone position on a homemade fixation plate,and the electroacupuncture group was given electroacupuncture treatment at EXB2(two segments above and below the injury site),the acupuncture group received only the same position of acupuncture intervention without power supply,and the injury group was only fixed in the same way without any intervention.The treatment frequency was2/100 Hz,the current intensity was about 1～2m A,and it was appropriate to have a slight tremor of the back muscles under the naked eye for 15 min each time,once a day,for 14 days of intervention.The motor function of the hind limbs of rats was assessed by the BBB scoring method at 3,7,and 14 days after surgery,respectively,followed by HE staining to observe the pathological recovery changes of spinal cord tissues,q RT-PCR to detect the m RNA expression levels of Hes3,Notch1,Notch3,and Notch4,and western blotting to detect the protein expression levels of Hes3 Notch1,Notch3,and Notch4.The expression of GFAP was detected by immunohistochemistry 14 days after surgery.Results: 1)After modeling,the BBB scores of the injury group,electro-acupuncture group,and acupuncture group were all 0,and the sham-operated group was 21,indicating successful modeling.2)The BBB scores of the electro-acupuncture and acupuncture groups were higher than those of the injury group at 3,7,and 14 days after EA intervention(P < 0.05),and the electro-acupuncture group was higher compared with the acupuncture group(P < 0.05).3)HE staining results showed that the spinal cord sections of rats in the sham-operated group showed a normal central canal,clear gray and white matter,plump nucleus,and no bleeding.The spinal cord tissue in the injury group showed obvious hemorrhage,structural destruction,and degeneration,and the hemorrhage gradually disappeared at 7 and 14 days after surgery,but the structure was still disorganized and vacuoles were visible,whereas the edema in the electroacupuncture and acupuncture groups was less than that in the injury group,the hemorrhage was reduced and the structure was restored,and the recovery effect in the electroacupuncture group was better than that in the acupuncture group.4)q RT-PCR and western blot results showed that the m RNA expression levels and protein expression levels of Hes3,Notch1,Notch3,and Notch4 were significantly higher(P < 0.05)after spinal cord injury,reaching a maximum at 7 days and decreasing at 14 days after surgery,while the electroacupuncture and acupuncture groups were generally significantly lower compared with the injury group(P < 0.05),and the electroacupuncture group tended to have a more significant effect(P < 0.05).5)Immunohistochemical results showed that the expression of GFAP increased after spinal cord injury surgery,but decreased significantly after electroacupuncture and acupuncture intervention(P<0.05),and there was no significant difference between the electroacupuncture and acupuncture group(P>0.05).Conclusions: 1)Electroacupuncture at EX-B2 could promote the recovery of motor function of hind limbs of rats with spinal cord injury,reduce hemorrhage and edema in spinal cord tissues,and promote structural repair.2)Electroacupuncture at the Jiaji points could inhibit the expression of Hes3 and the activation of the Notch signaling pathway after spinal cord injury.3)After 14 days,electroacupuncture significantly inhibited the formation of the pre-scar material GFAP,which we speculate might be related to the inhibition of the regulatory role of the Notch signaling pathway on the differentiation of neural stem cells to glial cells.4)Electroacupuncture was more effective than acupuncture in treating spinal cord injuries. |
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