Expression Of CD147 In The Spinal Cord And Dorsal Root Ganglia Of Rat Neuropathic Pain Model

CD147, a member of the immunoglobulin superfamily, is widely expressed in various tissues, originally identified as a tumor surface protein capable of inducing matrix metalloproteinase (MMPs) expression in fibroblasts. While increased expression of CD147 occurs in many tumors, its expression is not limited to tumor cells. CD147 is a pleiotropic molecule that is critical in fetal development and retinal function and has been shown to play a role in thymic T cell development, as well as many neurological processes ranging from the development of the nervous system to the involvement in spatial learning and plaque formation within Alzheimer?s stricken brains.It was documented that MMPs are invovled in the development and mantainance of neuropathic pain. We proposed a hypothesis that CD147, as a inducer of MMPs, may be directly involved in the development of neuropathic pain, and immune therapy targeted at this molecule might provide effictive means for the treatment of neuropathic pain. To provide evidence that CD147 is invovled in the development of neuropathic pain, immunofluorescence staining and western blotting were used to observe the expression of CD147 in the spinal cord (SC) and dorsal root ganglion (DRG) in a neuropathic pain model --- spinal never ligation model (SNL).1. The expression of CD147 in the SC of the rats after SNL. Behavioral tests were used to assess the success rate of the SNL models. Male SD rats (n=80) were randomly divided into two groups: sham operation group (Sham group) and SNL group. The results showed that the PWT and TWL in SNL group were significantly lower than that in the sham group after the surgery (P < 0.01). The PWT in SNL group reached a peak at day 7 and mantained at least untill day 21. The TWL in SNL group began to decline after 1d of surgery, reached a peak at day 3 and lasted to day 21. Immunofluoresence staining showed that there were no significant expression changes of CD147 between SNL and Sham group after 1,3,7d of SNL in the dorsal horn of the spinal cord.2. The expression of CD147 in the DRG of the rats after SNL. Immunofluorescence staining and western blotting showed that the expression of CD147 was significantly upregulated in the DRG of SNL group, comparing with sham group. The upregulaed expression of CD147 in SNL group reached a peak at day 3 and maintained untill day 21. Activation of GFAP is paralleled with CD147 in the dorsal root ganglion in SNL models. The CD147 stauing was mainly located in the stroma. Double-staining indicated that CD147 staining is not overlaped with neurons, satellite cells, fibroblasts and endothelial cells.Conclusions:The present study indicated that the expression of CD147 was upregulated in the DRGs, but not in the spinal cord, after SNL. The upregulated expression of CD147 is paralleled with the activation of GFAP and the development of mechanical allodynia and thermal hyperalgesia after SNL, suggesting its potential role in the development of neuropathic pain.