Effect of electroacupuncture intervention on the spinal cord PPIA/NF-κB signaling pathway in mice with amyotrophic lateral sclerosis.

Objectives: To observe the effects of electroacupuncture (EA) on motor function, expression of extracellular cyclophile A(PPIA) and PPIA/nuclear factor-κB (NF-κB) signaling pathway in spinal cord of amyotrophic la-teral sclerosis (ALS) mice, so as to explore the mechanism of EA intervention in regulating extracellular PPIA on neuroinflammation in ALS mice.

Methods: Thirty ALS-SOD1^G93A mice with hSOD1-G93A gene were randomly divided into model, EA and Riluzole groups , with 10 mice in each group, and other 10 ALS-SOD1^G93A negative mice were used as the blank group. EA was applied to bilateral "Yanglingquan"(GB34) and "Zusanli"(ST36) for 20 min once daily, 5 days a week for 2 weeks. In the Riluzole group, riluzole solution (30 mg·kg^-1·d^-1) was administrated intragastrically, and the treatment time was the same as that in the EA group.Rotating rod experiment and open field experiment were used to evaluate the changes in motor function of mice .The morphology of motor neurons in the anterior horn of spinal cord was observed by HE staining.The relative protein expression levels of PPIA, TDP-43 and NF-κB in the spinal cord were detected by Western blot.The positive expression level of TDP-43 in the spinal cord was detected by immunohistochemistry. The positive expression level of PPIA in spinal cord was marked by immunofluorescence. Serum PPIA content was determined by ELISA.

Results: Compared with the blank group, the time of rod dropping and the total distance of open field movement in the model group were shortened (P<0.01), the number of motor neurons in the anterior horn of the spinal cord was reduced, the cell morphology was incomplete, the cell body was atrophied, the protein expression and positive expression of TDP-43 were increased (P<0.01), the protein expressions of PPIA and NF-κB in the spinal cord were increased(P<0.01), the serum content of PPIA and immunofluorescence expression of PPIA in spinal cord were increased (P<0.01). Compared with the model group, the time of rod dropping and the total distance of open field movement of mice in the EA group and the Riluzole group were prolonged (P<0.05, P<0.01), and the injury of motor neuron in the anterior horn of the spinal cord was decreased, the protein expression and positive expression of TDP-43 in the spinal cord were decreased (P<0.05, P<0.01)；the relative expression levels of PPIA and NF-κB proteins were decreased (P<0.05, P<0.01), and the content of PPIA in serum and the immunofluorescence expression of PPIA in the spinal cord were decreased (P<0.05, P<0.01) in the EA group；the relative protein expression of NF-κB and fluorescence expression of PPIA in spinal cord of mice in the Riluzole group were decreased (P<0.05).

Conclusions: EA intervention can improve motor function in ALS mice, and its mechanism may be related to the inhibition of PPIA/NF-κB signaling pathway by EA to alleviating neuroinflammatory response.