The Effects Of Intrathecally Injected Of Human Umbilical Cord Mesenchymal Stem Cells On Neuropathic Pain In Rats

Objectives To observe the effects of intrathecal injection of human umbilical cord mesenchymal stem cells(h UC-MSCs) in rats with spinal nerve ligation(SNL) on neuropathic pain-(NP) like behaviors and the expression of inflammatory factors, the activation of glia(microglia and astrocytes) in spinal cord dorsal horn.Methods Forty-eight Male Sprague-Dawley rats weighting 150~200g without motor dysfunction after successful intrathecal catheter placement were randomly divided into three groups(n = 16): sham group(sham operation + cell cultures fluid group), control group(SNL + cell culture fluid group) and treatment group(SNL + h UC-MSCs group). Rats in sham group and control group were intrathecally injected of cell culture medium on day 3 after SNL. While rats in treatment group were intrathecally treated with h UC-MSCs on day 3 after SNL.Mechanical paw withdrawal threshold(PWT) and thermal paw withdrawal latency(PWL) were measured on Day 1 before surgery(baseline) and Day 3, 7, 14 d after surgery. Fresh spinal cord tissue were taken out after behavioral assessment on Day 14 after surgery. The expression of levels of inflammatory factors were measured by Enzyme linked immunosorbent assay(ELISA), astrocytes and microglia activation in spinal dorsal horn were measured by immunofluorescence and Western blot(WB).Results 1. Compared with the sham group, the PWT and PWL were decreaed at 3d, 7d, and 14 d after spinal nerve ligation(P <0.05). Compared with the control group, the PWT and PWL of treatment group were significantly increased at 7d and 14 d after surgery(P <0.05). 2. Compared with the sham group, the levels of pro-inflammatory cytokines in control group were significantly increased(P <0.05). Compared with the control group, the levels of pro-inflammatory cytokines in treatment group were significantly reduced(P <0.05). Compared with the control group, the levels of anti-inflammatory cytokine of treatment group were significantly increased(P <0.05). 3. Compared with the sham group,the expression of glial fibrillary acidic protein(GFAP) and ionized calcium adapter protein molecule 1(Iba-1) in control group was significantly increased(P <0.05). Treatment group compared with the control group, the expression of GFAP and Iba-1 was significantly reduced(P <0.05).Conclusions The intrathecal injection of h UC-MSCs can prevent and treat NP from SNL by reducing levels of pro-inflammatory cytokines and increasing levels of anti-inflammatory cytokines, suppressing activation of astrocytes and microglia.