Abstract:

Objective To investigate the effect of inhibiting aquaporin 4(AQP4) on the activation of glial cells and mitogen-activated protein kinase(MAPK) signaling pathway in sciatica caused by lumbar disc herniation. Methods Male SD rats(n=90) were divided into sham group(n=18), chronic compressive injury(CCI)+DMSO group(n=36) and CCI+TGN-020 group(n=36). Make CCI model. Test sample of spinal by Western blotting method and immunology chemical fluorescence double staining method . Results Western blotting showed the astrocytes and extracellular regulated proptein kinase(ERK), c-Jun N-terminal kinase(JNK), p38MAPK pathway were activated. Immunofluorescence found TGN-020 could inhibit the expression of AQP4, weaken the activation of glial cells induced by nerve injury, and affected the activation of ERK,JNK and p38MAPK signaling pathways. We also found that the number of cells expressing p-ERK and glial fibrillary acidic protein(GFAP) at the same time increased obviously after injury, and could be significantly reduced by TGN-020. Conclusion Inhibition of AQP4 can inhibit the activation of astrocyte and activation of MAPK signaling pathway of spinal dorsal horn, which are caused by sciatic nerve injury. Inhibition of AQP4 can reduce the activation of astrocyte by inhibiting activation of the ERK pathway in the astrocytes in spinal dorsal horn, and improving the neuropathic pain caused by sciatic nerve injury.

Key words:  Sciatic nerve injury, Astrocytes, Aquaporin 4, Mitogen-activated protein kinase signal pathway, Extracellular regulated protein kinase signal pathway, Immunofluorescence, Rat