Neuroinflammation In The Spinal Dorsal Horn In Deafferentation Pain And The Regulation Of Inflammation Through The Differentiation Of Microglia Following Bone Mesenchymal Stem Cells(BMSCs)Transplantation

Background:Dafferent pain is caused by peripheral or central sensory nerve injury and abnormal discharge of upstream neurons or c-type fibers caused by dafferent pain,which is a typical neuropathic pain.Currently,there is no effective treatment without obvious side effects.Central sensitization caused by a cascade of inflammatory responses between peripheral or central immune cells and central nerve cells after nerve injury is an important factor in the formation and maintenance of neuropathic pain.Bone mesenchymal stromal cells(BMSCs)are a kind of pluripotent stem cells with self-renewal and multidirectional differentiation ability.Both BMSCs transplantation have nerve to protect and promote nerve repair effect,BMSCs nerve protective effect mainly through paracrine regulation the host microenvironment,including:the main function of the experiment proves the immune adjustment,resistance to apoptosis,promote angiogenesis and promote the host stem cells/progenitor cell growth and differentiation,scarring,producing chemokines,etc.Therefore,this study intends to take this as a starting point to find a long-term pain relief treatment.Objective:1.To establish a model of neuronal afferent pain induced by posterior root injury of spinal nerve in rats,and to study the mechanism of neuronal inflammation in posterior root medullating area of spinal dorsal horn.2.BMSCs were transplanted into the posterior root entry zone of spinal cord for treatment to study the inflammatory regulation and pain relief effect of BMSCs.Method:1.Animal models of neuropathic pain were made,and their behavioral changes were detected at 3,7,10,14 and 21 days after the operation and 3 days after the transplantation.2.Expression levels of HMGB-1?ERK1/2?NF-kb?IL-6?IL-1a?TNF-? in spinal cord tissues of rats were detected by RT-PCR.3.The protein expressions of ERK1/2,p-ERK1/2,p-NF-kb,BCL-2 and IL-6 were detected by Western blot.The expression levels of IL-1a and TNF-? in serum were detected by ELISA.4.The spinal cord tissue was taken for paraffin section,and then immunohistochemical quantitative analysis,immunofluorescence detection of microglial cell types and Tunel staining were performed to detect the apoptosis rate of spinal cord nerve cells.5.Adopt SPSS20.0 software processed the data,and one-way anova was used for pairwise comparison between groups.When P<0.05,the difference was statistically significant.Result:1.After the modeling,the motor ability was not damaged,the limb function of the affected side was complete,and the modeling was successful.There was no significant change in pain-related behavior at the early stage,but significant change occurred 14 days after the operation and lasted for a long time,including limb protection and limb autophagy on the affected side.2.munohistochemical examination showed that there were significant changes in neuronal inflammation in the posterior root of spinal cord in the injured side after modeling,compared with the contralateral side,which mainly showed increased number and positive rate of cells of HMGB-1?IBA-1?GFAP?pNF-kb?IL-6?IL-1? and TNF-?.Western blot detected increased expression of HMGB-1,IL-6 and p-NF-kb proteins 3 days after modeling,while p-ERK1/2 started to increase expression 14 days after the surgery,and showed a significant difference compared with sham group 21 days after modeling,while p-NF-kb and p-ERK1/2 were significantly decreased and BCL-2 were significantly increased after BMSCs transplantation.The serum levels of IL-la and TNF-? were significantly increased 10 days after the operation by ELISA.Tunel staining in paraffin sections of spinal cord tissue showed that apoptosis in the injured spinal cord after BMSCs transplantation was significantly reduced.Co-localization of immunofluorescence indicated that the expression of M2-type microglia in the posterior root entry area of spinal cord was increased after BMSCs transplantation,while the expression of M1-type microglia was decreasedConclusion:1.After the introduction of entirely to,its movement function in good condition,no pain-related behavioral change in the short term,and after spinal root into the pith of chronic inflammation of nerve showed specificity of pain after the formation of related behavioral change,prompted the chronic nerve pain and spinal cord after root into the pulp inflammation have close relations,provides a theoretical basis for later treatment.2.After local BMSCs transplantation in the posterior root of spinal cord,local inflammation was controlled,pain related behaviors were improved,local cell apoptosis was inhibited,and microglia cell type changed from M1 to M2,which provided a basis for further revealing the therapeutic mechanism of BMSCs in this kind of pain.