Research On The Correlation Of Brain Edema And Prognosis In Rats After Traumatic Which Transplant EPCs

Background:Since Asahara and her team extracted CD34+from circulating blood in1997, and later scholars found it tend to transform into vascular endothelial cells,homing to the scar tissue and named it as Endothelial progenitor cells. It belongs to pluripotent stem cells family, colonization in the bone marrow. Migrate and differentiate into mature endothelial cells to the target region after trauma.It expresses the featurs of CD34+and CD133+. This discovery allows people to have a new understanding of angiogenesis,leading people to reconsider the way of promoting angiogenesis as well as the treatment of ischemic diseases In recent years,EPCs’s physiological characteristics and clinical application value more and more become a hot point. Warner found that peripheral blood EPCs were significantly increased in patients with acute myocardial infarction,and the higher the number, the lower the probability of occurrence of cardiovascular events and mortality. EPCs has successfully been applied in some ischemic diseases,such as limb ischemic disease, Cardiovascular disease and Primary pulmonary hypertension. There are two aspects of promoting angiogenesis mechanism:First, it can directly differentiate into neovascular. The second is the secretion of vascular endothelial growth factor (VEGF) to facilitate this process.Transplantation of exogenous vascular endothelial progenitor cells or using pro-angiogenic drugs to improve the content of the peripheral blood EPCs, can significantly improve the prognosis of ischemic diseases, especially cardiovascular disease.But there is lttle research in traumatic brain tissue ischemia. Reports in the literature a lot of post-traumatic cerebral infarction prognosis analysis and treatment experience, proving that in the presence of ischemic brain tissue after trauma and partial circulatory disorders.In the field of traumatic brain injury, Research direction is mostly concentrated in nerve regeneration, cerebral protection and suppression of cerebral edema,in which vasogenic cerebral edema (VBE) is recognized as brain trauma and cerebral hemorrhage, the most common type,causing brain herniation and leading to death. Destruction of vasogenic cerebral edema formation in most cases, and the blood-brain barrier (BBB), increased capillary permeability, plasma protein and moisture seeping increased. This process is mainly concentrated in the local microcirculation. Some scholars worry that the nascent capillaries will increase plasma protein and moisture oozing thereby increasing the formation of cerebral edema. Some people even try to use to inhibit angiogenesis drugs to relieve traumatic brain edema,which can increase the risk of post-traumatic cerebral infarction.Objective:1.To culture and identification of rat peripheral sources of EPCs in vitro.2. To transplanted EPCs through the tail vein into brain injury rats, observing the impact of the trauma area neovascularization.3. Rat brain water content was measured to estimate cerebral edema.4. Judgment transplanted EPCs angiogenesis, cerebral edema and prognosis though modified neurological severity scores (mNSS)Method:1.Extraction, in vitro culture and identification of EPCs:Open-chest and acquisition rat peripheral blood, gradient centrifugation monocytes after anticoagulant. Seeded in coated with fibronectin64-well plate,37°adherent cultured for2days, medium was changed every3days once. Observe cells with inverted fluorescence microscope. Express the markers of endothelial progenitor cells as CD34+/CD133+, Fluorescein-labeled acetylated low density lipoprotein uptake test and gorse lectin (FITC-UEA-1) experimental identification of endothelial progenitor cell function, the percentage of positive cells by flow cytometry.2. Rat brain injury model:120optional SD adult rats, divided into operation group and the sham group.And the operation group also divided into EPCs group, inhibit angiogenesis group and blank control group.All three groups underwent moderate traumatic brain injury blow. Mouse tail vein graft endothelial progenitor cells, inhibits angiogenesis group to give local and mouse tail vein injection of VEGF antibody, cell culture medium of blank control group rat tail vein injection of the same amount given EPCs group in24hours after injury. Sterile diet for two weeks.3.Nervous system score:Each group of rats daily improved modified neurological severity scores (mNSS) assess the extent of damage and recovery of the nervous system in rats.4. Assessment of cerebral edema:Taken10in day3, day7and day14random numbers from the three groups of rats. Infusion of saline100ml into ascending aorta after anesthesia.Remove the brain and weighed. Placed in50%sucrose solution dehydration sink to the bottom, again weighing between brain water content calculated subtraction.5. The degree of angiogenesis observed:After dehydration brain tissue is placed in4%paraformaldehyde and fixed overnight. Consecutive paraffin sections though trauma area. Immunohistochemical CD34+, CD133+and count the positive cells, staining was observed the trauma region skin vascular progenitor cell aggregation and angiogenesis situation.6. Data Analysis:Using statistical softwar for three sets of data obtained were statistically analyzed. Determine whether there is statistically significant.Result:Determination of water content in the brain tissue, the brain tissue of EPCs group average water content (77.26±2.24)%, the vasodepressor group average brain tissue water content (74.71±1.85)%, average moisture content of the brain tissue of the control group(75.48±1.92)%, pairwise comparisons of the three sets of data the differences were statistically significant (P<0.05). In nervous system function injury score EPCs group scored significantly higher than the other two groups, while the the vasodepressor group and blank control group score difference was not statistically significant. CD34+and CD133+immunohistochemical staining positive cells, EPCs group were counted far more than the other two groups, while the statistical analysis, the number of cells with endoscopic positive prognostic score was positively correlated with brain tissue water content had no significant correlation. Conclusion:Transplantation of exogenous endothelial progenitor cells (EPCs) to some extent can aggravate cerebral edema. The application of anti-angiogenic drugs can reduce the formation of brain edema However, due to reduced blood supply of the trauma in the brain tissue, representing an increase of ischemic necrosis of the brain tissue area, but not conducive to the prognosis. In short, the prognosis and long-term efficacy, given exogenous brain injury patients transplanted EPCs do more good than harm.