Electro-Acupuncture Modulates L1 Adhesion Molecule Expression After Mouse Spinal Cord Injury

Abstract

Spinal cord injury is a devastating neurological disease in desperate need of a cure. We have previously shown that overexpression of the adhesion molecule L1 contributes to locomotor recovery after injury and were therefore interested in how electro-acupuncture would influence the expression of this molecule. Here, we investigated the effects of electro-acupuncture at "Jiaji" points (EX-B2), newly established by us, in young adult mice to determine whether improved recovery via electro-acupuncture could be due to enhanced L1 expression. Locomotor function, as evaluated by the Basso Mouse Scale score and by catwalk gait parameters, was improved by electro-acupuncture at different time points after injury in parallel with enhanced levels of L1 expression. Interestingly, the levels of the astrocytic marker glial fibrillary acidic protein (GFAP) were also increased, but only in the early phase after injury, being reduced at later stages during recovery. Acupuncture alone showed less pronounced changes in expression of these molecules. We propose that electro-acupuncture improves regeneration in part by promoting the L1 expression and beneficial activation of stem cells, and by differentially modulating the expression of GFAP by promoting regeneration-conductive astrocytic responses at initial stages and reducing regeneration-adversive activation in the secondary stages. Expression of the stem cell marker nestin was upregulated by electro-acupuncture in the acute stage. The combined observations show for the first time in mice the beneficial functions of electro-acupuncture at Jiaji points in the spinal cord injury mouse model and provide novel insights into some molecular mechanisms underlying electro-acupuncture in spinal cord injury.