Research On Cognitive And Behavioral Function After Transplanting Morrow Stromal Cells Into Lateral Ventricle Of Traumatic Brain Injury Rats

ObjectiveIn this study, the marrow stromal cells(MSCs)of Green fluorescent protein(GFP)-SD rats were transplanted into lateral ventricle of rats subjected to traumatic brain injury(TBI), to observe the survival, migration and differentiation of the MSCs and to investigate whether cognitive and behavioral function are improved.Methods①The MSCs were obtained from Green fluorescentprotein (GFP)-SD rats, and cultured in vitro. The MSCs maker CD44(+)、CD90(+)and CD11b(-) were used to identify the cultured MSCs.②The fifth generation MSCs were digested by0.25%trypsindigestion, Iscove’s Modified Dulbecco’s Medium (IMDM) adding10%Fetal Bovine Serum(FBS) was used to stop digesting. The density of MSCs suspension (1×106/10μl) was calculated and prepared for transplantation.③96SD rats(250g) of clean degree were selected,and divided into four groups.(1) normal control group:rats (n=24) were randomly selected. The other72rats were used to establish TBI models by using Feeney free-failing method.Seven days later, the72TBI rats(n=72) were randomly divided into three groups;(2) TBI control group(n=24): nothing were injected into lateral ventricle of TBI rats;(3) MSCs transplanted group (n=24):MSCs (1×106) in10μl of IMDM were injected into lateral ventricle of TBI rats;(4) IMDM control group(n=24):10μl IMDM were injected into lateral ventricle of TBI rats.④Modified neurological severity score (mNSS)(including rotation test, physical strength test, balance test) and the Morris water test were performed to evaluate the function of central nervous system(CNS) through testing of five consecutive days at2、4、8、12weeks after transplantation of MSCs in all four groups rats. Rats were killed after the end of the test. Nissl staining was used to observe the injury degree of TBI rat brain, Immunfluorescence staining was used to observe the MSCs’s survival、migration and differentiation.Results1In the fifth generation MSCs, the positive expression rate of the MSCs marker CD90(+) or CD44(+) is more than95%, the expression rate of the MSCs’s negative marker CD11b (-)is less than5%.2Nissl staining showed that the cortical structure of TBI rats defected seriously, neural glia cells were increased around the edge of the damaged zone.3The results of mNSS tests showed that the function of central nervous system(CNS) in MSCs transplanted groups were better than TBI rats; Compared to IMDM control groups and TBI control groups, the function of CNS in MSCs transplanted groups showed significantly amendment at the4,8and12weeks after transplantation,but there is no difference among three groups at the2weeks after transplantation. And there is no difference between IMDM control groups and TBI control groups4The results of Morris water maze tests showed that the normal group rats’escape latency was longer and the times of probe at goal region was shorter than normal group rats.Compared to IMDM control groups and TBI control groups, MSCs transplanted groups showed significantly amendment at the4,8and12weeks after transplantation.But there is no difference among three groups at the2weeks after transplantation. And there is no difference between IMDM control groups and TBI control groups.5Two weeks after transplanted, MSCs gathered in the lateral ventricle; but four weeks after transplantation, a lot of MSCs migrated to injured cortex, and much more MSCs migrated to the injured cortex in8and12weeks after transplantation. The immunofluorescence staining discovered that about1%and5%transplanted MSCs express GFAP and NeuN phenotype.Conclusions17days after TBI in rats. TBI rats’ brain cortex tissue defected seriously, a large number of neural glia cells could be seen around the edge of the damage zone;2The exercise capacity and cognitive function of MSCs transplanted rats becomes much better after transplantated MSCs than other TBI rats;3MSCs could survival and migrate to injured cortex of TBI rats;4Less MSCs could express GFAP and NeuN phenotype;5The MSCs can be used as the resource for cell transplantation.