Umbilical Cord Mesenchymal Stem Cells For Inflammatory Regulation After Rats Severe Burn Wounds Excision And Grafting

Objective:In vitro animal experiments to explore the inflammation of severe burns after excision,then during this situation,Umbilical cord mesenchymal stem cells were used to observe their inflammatory regulation in the body and effects on the skin grafts,The purpose is to accelerate the transformation of stem cells in the clinical application of burns.Methods:1.Firstly,To investigate the inflammatory changes after severe burn excision,SD rats were randomly divided into 3 groups.The model group:a 30%?-degree burn model of SD rats was established and the fluid was anti-shock routinely;Then the excision was operated and covered with allogeneic mesh skin graft;the sham operation group:anti-shock after scald at 37?,and simulated the operation of excision and covered with allogeneic mesh skin graft.Each group was taken at the following time points:model group 12h,24h,48h,72h,96h,excision group:24h,48h,72h,96h,sham group:24h,48h,72h,96h,Each group had 5 rats at each time point.Serum was used to detect LBP,HMGB-1,IL-6,TNF-?,and IL-10 inflammatory factors by ELISA.Western blot was used to detect the expression of P38MAPK/NF-?B inflammatory signaling pathway in rat liver.2.Although the shock stage excision can reduce inflammation,but there are still a lot of inflammatory factors exist in the body,it is harmful for new transplantation of autologous skin,so after severe burn we excision and grafting.At the same time,umbilical cord mesenchymal stem cells were injected into the caudal vein,To explore the inflammatory regulation function of mesenchymal stem cells for transplantation of skin effect.The SD rats were randomly divided into 4 groups:normal group:30%? degree scald model 24h after excision and graft surgery;sham group:simulated excision and skin grafting after scald at 37?;normal+hUCMSCs group:caudal vein injection of umbilical cord mesenchymal stem cells(3×106cells/each,1ml)was performed on normal group;normal+SB203580 group:SB203580(10mg/kg,1ml),a P38MAPK pathway inhibitor,was injected into the tail vein.Each group was sampled 1d,2d and 3d after surgery,Serum was used to detect LBP,HMGB-1,IL-6,TNF-?,and IL-10 inflammatory factors by ELISA.Western blot was used to detect the expression of P38MAPK/NF-?B inflammatory signaling pathway in rat liver,trypan blue staining for transplant skin active verification and Western blot detection skin grafts necrosis marker protein RIP3?HE dyeing observation skin grafts inflammation infiltration and immunohistochemical determination of skin grafts in macrophage polarization patterns.Results:l.The levels of LBP,IL-6,TNF-? and IL-10 in the serum of the model group gradually stabilized after reaching the peak at 12h?48h.and HMGB-1 gradually increased and reached the peak at 96h(p<0.01).Compared with the model-group,the excision eschars grafting group and the sham operation group showed a significant decrease(p<0.01)or(p<0.05)in the inflammatory factors above LBP,and there was no significant difference in liver P38MAPK,phosphorylation P-P38MAPK.Phosphorylation of P-NF-Kb was significantly decreased(p<0.01)or(p<0.05).The above inflammatory factors and liver protein phosphorylation levels were significantly decreased compared with 24h in the excision eschars grafting group(p<0.01)or(p<0.05).2.normal+hUCMSCs group could regulate the phosphorylation levels of P38MAPK and NF-B P65 proteins in the liver to reduce the inflammatory response(p<0.01)or(p<0.05),and the effect was almost same as the normal+SB203 580 group.These effects could continue reduce the production of inflammatory factors HMGB-1,IL-6 and TNF-?(p<0.01)or(p<0.05),and increase the anti-inflammatory factor IL-10(p<0.01)or(p<0.05).the infiltration of inflammatory cells in skin graft was significantly reduced in the normal+hUCMSCs group,and the macrophages in the hUCMSCs group polarized to the anti-inflammatory M2 direction in 3d(p<0.05).Although hUCMSCs immune regulation effect is obvious,but failed to observe the rescue of early transplantation skin grfts activity and the change of necroptosis markers protein RIP3Conclusion1.Excision during shock phase can reduce the production of inflammatory factors and is related to the classical inflammatory activation pathway P38MAPK/NF-B.2.There are still a large number of inflammatory factors in the body after excision in severe burns.Umbilical cord mesenchymal stem cells can reduce the inflammatory response after excision and skin grafting through the P38MAPK/NF-B inflammatory pathway,and reduce the production of inflammatory factors and the infiltration of inflammatory cells in the skin graft.