Electroacupuncture stimulation inhibited astrogliosis and microglia polarisation to alleviate spinal cord injury via Janus kinase 2/signal transducer and activator of transcription 3 signalling pathway

Abstract

Introduction: The aberrant activation of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway is involved in spinal cord injury (SCI) progression. Electroacupuncture (EA) stimulation is effective in alleviating SCI, but the mechanism is poorly understood.

Material and methods: An SCI model was constructed by cord contusion at T10, and AG490 (a JAK2 inhibitor) served as a positive control in this study. We evaluated the effects of EA on locomotor activity and spinal damage in SCI rats. The effects of EA on astrocytes and microglia and on the JAK2/STAT3 signalling pathway in the cells were investigated.

Results: Behavioural tests showed that hind limb motor function of rats was improved after EA stimulation. The therapeutic effects of EA stimulation in restoring motor function, alleviating injured spinal cords, and inhibiting spinal cord neuronal apoptosis in SCI rats, were similar to those of AG490. Increased STAT3 activation was observed in astrocytes and microglia in the spinal cord of SCI rats, and this was reversed by EA stimulation. EA alleviated astrogliosis and inhibited microglia M1 polarisation in SCI rat spinal cords. In addition, RNA expression levels of pro-inflammatory factors IL-6, CXCL1, and TNF-α in rat spinal cords were suppressed by EA stimulation, while the expression level of the anti-inflammatory factor heme oxygenase 1 was increased. Meanwhile, the expression of p-JAK2, p-STAT3, and JAK2/STAT3 downstream targets SOCS3 and COX-2 in the spinal cord of SCI rats was inhibited by EA stimulation. Interestingly, the observed effects were comparable to those treated with EA.

Conclusions: Our findings demonstrate that EA stimulation ameliorates SCI in rats and exerts an inhibitory effect on the JAK2/STAT3 signalling pathway.

Keywords: AG490; JAK2; STAT3; electroacupuncture; spinal cord injury.