Inflammatory profiling of the satellite glial cells in the dorsal root ganglia of rat experimental neuropathic pain models
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| Year of publication | 2013 |
| Type | Conference abstract |
| MU Faculty or unit | |
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| Description | The satellite glial cells (SGC) envelope the primary sensory neurons of the dorsal root ganglia (DRG) and react intensely to various types of nerve injury that induce neuropathic pain. Unilateral chronic constriction injury (CCI, n=64) and spare nerve injury (SNI, n=32) of the rat sciatic nerve well as i.p. application of paclitaxel (PAC, n=12) were used as experimental models of neuropathic pain (NPP). NPP induction was tested by withdrawal threshold of mechanoallodynia and thermal hyperalgesia. Expression of TNFa, IL-6 and their receptor and signaling (TNFR1, TNFR2, IL-6R, gp130, STAT3) proteins and mRNA were investigated bilaterally by immunohistochemistry and in situ hybridization in both lumbar (L4-5) and cervical (C7-8) DRG 1, 3, 7 and 14 days from treatment. The SGC were identified by colocalization with GFAP or GS. Our results demonstrate significant inflammatory activation of the neurons and their SGC not only in DRG associated but also non-associated with injured nerve. A distinct expression of cytokines and their receptors was identified in SGC surrounding large-sized DRG neurons. Significant inflammatory reactions of SGC were found in all DRG of PAC-treated rats. Moreover, inflammatory activation SGC was also observed in DRG of sham-operated rats indicating other kinds of trigger than traumatic nerve injury. The nerve injury and PAC-treatment also triggered SOCS3 expression in SGC to control STAT3 activation. Inflammatory activation of SGC significantly contributes to ectopic activation of the DRG neurons not only associated with injured nerve, and is involved in NPP induction. |
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