The Effect Of Bone Marrow Mononuclear Cells Transplantation On Brain Injury After Intracerebral Hemorrhage In Rats

Background and ObjectivesIntracerebral hemorrhage(ICH) is a primary non-traumatic brain hemorrhage,having a high incidence of each year. It is a common and often disability, fatal strokesubtype. However, It is aslo lack of effective treatments at present. The mechanismsof brain injury after Intracerebral Hemorrhage includes the hematoma compression,brain edema, inflammation and cell apoptosis. A mass of evidence indicates thatinflammation appears to be a key factor of secondary brain injury during the acutephase of ICH.Therefore, those demonstrate that anti-inflammatory therapy mayalleviate the aftermath of haemorrhagic stoke. And it is very important to alleviate theInflammation for reducing neurological damage aftermath and improving the qualityof life of patients. Cell therapy has gained much attention as an alternative approachto treat Neurological diseases. Bone marrow-derived cells(Bone marrow mononuclearcells, BMMNCs) comprise mesenchymal，hematopoietic stem cells and endothelialprogenitor cells (EPCs), progenitor and differentiated cells, et al. which is formed bya variety of heterogeneous group. BMMNCs has been shown as a good therapeuticmethod to treat cerebrovascular disease,which has many superiority, such as easyextraction and obtaining, avoiding immune rejection, autologous allografts, withoutculturing, no ethical and moral controversy. A lot of evidence has shown that BMMNCs transplantation on the treatment of heart and lower limb ischemic diseasesof animal experiment and phase1clinical research is safe and effective. However,weather there is nerve protective effect to hemorrhagic stroke of BMMNCstransplantation, having no relevant report at present. In the present study, weinvestigate the recovery of neurobehavioral function, brain edema, neuronal apoptosis,and the microglial/astrocyte activation and neutrophil infiltration in the ipsilateralbrain after administration of BMMNCs in ICH animal model. It is further toinvestigate the efficacy of BMMNCs treatment on outcomes in ICH animal modeland the possible mechanism of its effect on neuro-inflammation response.MethodsExperimental ICH models were performed by stereotaxic injection collagenaseⅣinto caudate putamen, Sham group was induced with a stereotaxic needle insertionand an injection of equal volume (2μl) of saline instead of collagenase. Rats with250-300g weight that underwent ICH were randomly divided into four groups: shamoperation group, ICH group, BMMNC-treated group, PBS group. Before obtainBMMNCs from donor rats, these rats were intraperitoneally injected of BrdU a totalof14days. BMMNCs were extracted, separated and purified by Ficoll-Paquedensity-gradient method; and BMMNCs were marked with Brdu for the tracer in thebody. Six hour after ICH induction, BMMNCs were administered intravenously byfemoral vein (3×107ml PBS/rat).And the ICH-vehicle group administered vehicle byinjecting1ml of PBS via femoral vein at6h after the ICH induction successful. Theneurobehavioral function was evaluated on days1,3,7,14by the modifiedneurological severity score, the brain edema was examined by wet-dry weightingmethod on day3after cell transplantation, and neuronal apoptosis was examined byFJC staining, Immunofluorescent staining was used to identify the number ofactivation of microglia and infiltration of neutrophils in the brain after ICH. TheBMMNCs marked with Brdu was also traced by immunofluorescent staining in thebrain. Results1. Sham group has no neurological defects on days1,3,7,14, and the result ofneurological score is0.The neurological defects of ICH group and PBS group werethe most serious on day1after ICH operation, and were start recovery on day7,wereobvious recovery on day14.The neurological score in BMMNC-treated group on day7,14was significantly improved compared with those of in ICH group and PBS group（P＜0.05）. Compared to the ICH group and PBS group, there was a significantdecrease in the brain water content in BMMNCs group on day3after ICH operation（P＜0.05）,and there was a significant decrease in the number of neuronal apoptosisin BMMNCs group on day3after ICH operation（P＜0.05）.2. In the ipsilateral brain, the BMMNCs group can see several the cells withBrdu on day1after ICH, the most of the cells with Brdu on day3after ICH, and thecells with Brdu begin to fall on day7after ICH. The number of activation ofmicroglia and infiltration of neutrophils were both significantly lower in BMMNCgroup compared to ICH group and PBS group, respectively（P＜0.01）.Conclusions1. BMMNCs can migration， home to ipsilateral brain and survive, cansignificantly alleviate the brain edema, decrease the number of neuronal apoptosis,improve neural functional recovery.2. BMMNCs can inhibit the activation of microglia and infiltration ofneutrophils.3. BMMNCs can treat the brain injury after intracerebral hemorrhage, whichmay relate to inhibit the inflammation of secondary brain injury after ICH.