Syudy On Treatment Of Spinal Cord Injury With Co-transplantation Of Human Umbilical Cord Mesenchymal Stem Cells And Rats’ Activated Schwann Cells

[Objective] To explore the growth characteristics of human umbilical cord mesenchymal stem cells (hUCMSCs) and rats’activated schwann cells(rASCs) respectively, analysis of the interaction between these two cells, to observe the effect of co-transplantation of hUCMSCs and rASCs on the recovery of acute spinal cord injury.[Method] hUCMSCs are derived from the full-term umbilical cords from healthy children and were cultured and passaged in vitro. Surface antigens and cell cycle of hUCMSCs were detected by FACS. The differential abilities of hUCMSCs into osteoblast, adipocyte and neurocyte were also tested. Activate Schwann cells were obtained through ligation of saphenous nerve of wistar rats, were expanded and purified. And in vitro activated Schwann cells and umbilical cord mesenchymal stem cells were co-cultured by using a Millicell culture insert, analysis the interaction between these two cells, the differential situation were tested by neurofilament immunofluorescence staining.80female Wistar rats (77±2d) were randomly assigned to4different study groups as follows:DMEM control group (group Ⅰ):10%DMEM injection; hUCMSCs group(group Ⅱ); rASCs group(groupⅢ); Co-transplantation group (group Ⅳ). Establish acute spinal cord contusion model (T10) by IMPACTOR MODEL-Ⅱ device. The recovery of the lower extremity were observed using Basso-Beattie-Bresnahan(BBB) locomotor scoring system, immunohistochemical stain to detect the survival and differentiation of hUCMSCs. And then observe the corticospinal tract (CST) using the biotinylated dextran amine (BDA) tracing. Using analysis of variance (ANOVA) and SNK-q for statistical analysis, comparing the group’s significant difference.[Results] A population of human umbilical cord derived MSCs were isolated from human umbilical Wharton’s jelly, they were processed to obtain a fibroblast like population of cells and could be maintained in vitro for extended periods with stable population doubling, and they were expanded as undiferentiated cells in culture for more than10passages. FACS revealed that hUCMSCs expressed MSCs markers, like CD73, CD105, but not hematopoietic and endothelial cell markers, such as CD34, CD45, and also did not express HLA-DR. hUCMSCs can differentiate into osteoblast, adipocyte and neurocyte under certain culture condition which were confirmed by morphologic changes and specific immunohistochemical staining. ASCs were separated and passaged stability for4generation, and purified satisfied according to differential cell adhesion and transferring under low enzyme concentration. The purity of ASCs is above90%. hUCMSCs and ASCs grew well when co-culture in millicell insert and some hUCMSCs show neuroeyte-like cell and expressed nestin and NF200which indicated neuron-dieffrentiation. BBB score was higher in cell transplant group than the DMEM control group4weeks after injury, the statistical difference was significant (P<0.05), co-transplantation group had a higher score than hUCMSCs group (P<0.05).Both the number of survived hUCMSCs and Positive response area in immunohistochemistry staining is larger in co-graft group than that in other groups (P <0.05). Anterograde tracing shows more regenerated nerve fibers get through injuried area in co-graft group which also has the smallest injuried cavity comparing with other groups.[Conclusion] hUCMSCs have strong proliferation property and can stably passaged for several generations, expressed surface markers like other MSC and have the ability of differentiate into other cell lineage under certain condition as stem cell. ASCs can successfully obtained by culture of pre-injured peripheral nerve. hUCMSCs can differentiate towards neurocyte lineage by co-culture with ASCs in vitro. AASCs can support hUCMSCs to survival and differentiation into neural cells, co-transplantation of hUCMSCs and AASCs was more effective in promoting functional recovery and axonal regeneration after SCI. significance. The hUCMSCs are capable of diferentiating into neuroeyte-like cells and they may represent an alternative stem cell source for CNS ceils transplantation.