Study Of Mild Hypothermia Combined EPO Affect The Expression Ofβ-amyloid (Aβ) In Traumatic Brain Injury (TBI) Model In Vitro And In Vivo

Objective:By detecting the amount of AP express in body fluids of clinical brain damage patients’, to confirmed their participation in the progress of brain damage; Construct pIRES2-EGFP-APP recombinant vector, then transfection the SH-SY5Y cell line, build model of the stable expression of Aβ in vitro, and use the mild hypothermia method to confirm the protective effect; then build TBI model, give mild hypothermia and EPO combined mild hypothermia intervention, to find new therapeutic targets for brain injury, find a new direction for early clinical intervention.Methods:The study includes three parts.Part one:60cases of clinical samples were detected, respectively, Take Oh,24h,48h,72h specimens of CSF, peripheral blood after admission, ELISA detection, and use GCS score evaluation prognostic, testing Aβ changes in the cerebrospinal fluid and serum and it’s relative with prognosis.Part two:Construct pIRES2-EGFP-APP recombinant vector, cultured SH-SY5Y cells then transfected with the recombinant vector, western-blot analysis detect APP expression, to build a stable expression of APP cell model; on this basis, given at room temperature and mild hypothermia training, detection of cell growth under different temperature conditions.Part three:Preparation of TBI model, the rat model then given an ice pack wrapped head within30minutes until temperature dropped to31℃C, maintain the temperature fluctuations at31-33°C in5hours:later the temperature rose to37.5-38.5℃. after injury, rhEPO group given intra-abdominal in jection (5000IU/kg) of rhEPO, postoperative intramuscular penicillin every12h sodium400,000U per day. to detect serum and cerebrospinal fluid AB content in0.5h,2h,6h,12h,24h,48h,72h by ELIS A. Western-blot analysis detected brain tissue AB expression with different interventions.Results:The first part of the experimental shows Aβ increased gradually change over time in brain injury patients, mechanisms of traumatic brain involves neurons injury, glial cell and the BBB injury, thus making Aβ in the collapse of the cytoskeleton released into the cerebrospinal fluid and blood circulation, the level was positively correlated with degree of injury. The second part selected eukaryotic vector transfected SH-SY5Y cell lines, with the cell-based labeling technique build model successful. Further evidence of the stable expression of the APP gene in transfected cell lines get by Western-blot and the protective effect of mild hypothermia on cell damage was confirmed. The third part was research in vivo and, was successfully constructed a TBI model, the feasibility of the model was examined through the nervous system score, then treated with mild hypothermia, the EPO combined with mild hypothermia intervention, confirmed the change of brain function after mild hypothermia EPO can effectively protect the brain damage.Conclusion:Aβ can promoting nerve growth, and reduce the neuronal damage; the treatment of mild hypothermia in vitro models confirmed a certain degree of protection; EPO combined with mild hypothermia intervention can effectively protect the brain damage in vivo, and show new therapeutic targets and theoretical basis in treatment of traumatic brain injury.