Abstract
Although neuropathic pain is one of the most intractable diseases, recent studies indicate that systemic or local injection of bone marrow stromal cells (BMSCs) decreases pro-inflammatory cytokines release and alleviates neuropathic pain. However, it is still not clear whether pre-treated BMSCs have a strong anti-inflammatory and/or analgesia effect. Using the spinal nerve ligation model of neuropathic pain, IL-1β pre-treated BMSCs (IL-1β-BMSCs) were injected into rats followed by SNL in order to determine possible effects. Results indicated that IL-1β-BMSCs were more efficacious in both amelioration of neuropathic pain and inhibition of microglia activation. Specifically, microglia inhibition was found to be mediated by chemokine C-C motif ligand 7 (CCL7) but not CCL2. Results also showed that IL-1β-BMSCs had a stronger inhibitory effect on astrocyte activation as well as CCL7 release, which was found to be mediated by IL-10 not transforming growth factor-β1. In addition, we also found directional migration of IL-1β-BMSCs was mediated by inceased C-X-C motif chemokine ligand (CXCL) 13 expression following SNL. In conclusion, our results indicated IL-1β-BMSCs could inhibit microglia activation and neuropathic pain by decreasing CCL7 level in spinal cord.