Effects of electro-acupuncture on remyelinization after compressive spinal cord injury / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effects of electro-acupuncture on the expression and inhibition of DNA binding protein 2 (Id2) and myelin basic protein (MBP),and to explore the mechanism of remyelinization after compressive spinal cord injury (CSCI) in rats.Methods Fifty-four SD rats were randomly divided into a control group and a treatment group,and each was further subdivided into 3 time point subgroups3,7 and 14 days.There were 9 rats in each subgroup.The CSCI models were made with a self-designed method.The acupuncture points Jiaji (EX-B2),bilateral Zusanli (ST36) and Taixi (KI3) were selected for treatment.Electro-acupuncture (continuous wave,2 Hz,1.5 V)was applied to the bilateral Zusanli (ST36) and Taixi (KI3) points.The control group received the injury but no treatment.The changes in the ultrastucture of the nerve fibers＇ white matter were de-termined by transmission electron microscopy (TEM).The alterations in the expression of MBP and Id2 were observed by double labeled immunofluorescence and Western blotting on the 3rd,7th and 14th day after the injury.Results TEM showed that the myelin sheaths in the control group had degenerated,swollen,and even broken down after CSCI.Changes to the myelin sheaths in the treatment group were milder than those in the control group.The immunofluorescence results showed the amount of Id2-immunoreactive oligodendrocytes in the control group to be (20 ±2) on the 3rd day after CSCI,becoming (16 ± 1) on the 14th day.The differences among the 3 control subgroups were not statistically significant.The amount of Id2-immunoreactive oligodendrocytes in the treatment group was (13 ± 1) on the 3rd day,reaching a minimum the 14th day.The differences among the 3 treatment groups were statistically significant.The differences compared with the control group at the same time points were also statistically significant.Western blotting showed that the expression of Id2 in the contrast and treatment groups was (1.12 ±0.12) and (0.67 ±0.01) respectively on the 3rd day after CSCI,and both decreased with time.The expression of Id2 in both groups reached their minima ((0.86 ±0.02) and (0.25 ±0.01) respectively) on the 14th day.The difference between the treatment groups and the contrast group was statistically significant at each time point.The expression of MBP in the contrast and treatment groups at day 3 was (0.44 ± 0.02) and (0.67 ± 0.04) respectively,and these increased with time.The expression of MBP in both groups peaked at the 14th day (at (0.95 ± 0.04) and (1.74 ± 0.09) respectively).These differences were again statistically significant.Conclusion Electro-acupuncture can regulate the expression of Id2 and MBP after CSCI.The down-regulation of Id2 which controls MBP negatively and the up-regulation of MBP may contribute to remyelination in the injured spinal cord.