The Experiment Of The Effects Of EPOR On RH-EPO Angiogenesis In Premature Rat With Brain Injury Through ERK Signaling Pathway

Objective: To observe the influence of EPO on MEK/ERK signaling pathway by establishing the hypoxic-ischemic brain damage model through the three-day-old rat.To a certain degree,it illuminates that EPOR is the key role in upstream of RH-EPO angiogenesis effect in rat premature brain injury model through ERK signaling pathway.Methods: All of the 3-days postnatal rats were randomized divided into five groups: the sham group(without hypoxia-ischemia(HI));the HI group(HI with saline administration),and the HI+erythropoietin(EPO)group(HI with recombinant human erythropoietin(rh-EPO)administration);and the HI+anti-EPOR group(HI with anti-EPOR administration);and HI+EPO+anti-EPOR group(HI with recombinant human erythropoietin(rh-EPO)and anti-EPOR administration).Rat pups underwent permanent ligation of the right common carotid artery,followed by 6% O2 for 2 hours or sham operation and normoxic exposure.the HI+anti-EPOR group and HI+ EPO+anti-EPOR group after the operation,rats received a single intraventricular injection of anti-EPOR(5ul).HI+ erythropoietin(EPO)group and HI+ EPO+anti-EPOR group after HI,rats received a single enterocoelia injection of rh-EPO(5IU/g).EPOR ? phosphorylation-EPOR ? ERK and phosphorylation-ERK were examined at 60 minutes and 90 minutes after group processing,and VECFR2 were detected at 2 and 4 days after group processing by using Western bolt.Postoperative 2D,4D each group were taken more than 6,free of rats in the right cerebral hemisphere,real-time fluorescence quantitative polymerase chain reaction method for detection of VEGF?ang-1 mRNA.Result: At 60 and 90 minutes after group processing,the expression of EPOR protein in the rat brain tissue was lower in the sham group,but higher in HI group?HI+EPO group and HI+EPO+anti-EPOR group(P<0.05).The expression of EPOR protein in HI+EPO group showed higher than HI group and HI+EPO+anti-EPOR group.And in HI+anti-EPOR group,the expression was lower than the HI group.The differences were statistical significance(F=30.154?20.265,P<0.05).The expressions of P-EPOR,P-ERK,and VEGFR2?CD34+ after 2 and 4 days of group treatment were consistent with the expression of EPOR,and the differences were statistically significant(P<0.05).4 days after group processing,the VEGFR2 expression in HI+EPO+anti-EPOR group was lower than it in HI group(F = 54.248,P < 0.05).60 and 90 minutes after completion packet processing,there was no statistically significant in ERK expression between each group(F=1.117?0.734,P>0.05).2 days after group processing,there was statistical difference(P < 0.05)of VEGF mRNA,between the HI group and sham group?HI+ anti-EPOR group,HI+rh-EPO group and the other groups,HI+ rh-EPO+ anti-EPOR group and HI+ anti-EPOR.4 days after group processing,there was statistical difference(P < 0.05)of VEGF mRNA,between the HI+ anti-EPOR group and HI group,HI+rh-EPO group and the other groups,HI+rh-EPO+ anti-EPOR group and sham group,HI+ rh-EPO+anti-EPOR group and HI+ anti-EPOR group,respectively.2 and 4 days after group processing,there was statistical difference(P < 0.05)of Ang-1 mRNA,between the HI group and sham group?HI+ anti-EPOR group,HI+rh-EPO group and other groups,HI+ rh-EPO+ anti-EPOR group and HI+ anti-EPOR group,respectively.Conclusion : The hypoxic-ischemic brain damage in three-days-old immature rat is in step with the neuropathologic change in premature brain white matter damage.In a rat premature white matter damage model,when EPOR is blocked,the regulation of EPO on the CD34+?VEGF?Ang-1 and VEGFR2 expression through ERK signaling pathways will be influenced.