不同成熟度大鼠脑组织促红细胞生成素受体的表达及脂多糖对其表达的影响

摘要

目的探讨不同成熟度大鼠脑组织促红细胞生成素（EPO）受体（EPO-R）的表达及脂多糖（LPS）对不同成熟度大鼠脑组织EPO-R表达的影响。方法2日龄（Postnatal day 2，P2）新生SD大鼠，随机分为A、B两组：A为正常对照组，B为LPS组，分别腹腔注射等容积0.9%氯化钠注射液或0.6 mg/(kg·d)的 LPS，连续应用5天（P2~P6），并续养至12日龄（P12）。A组于P2、P7、P12及B组于P7、P12各时间点随机抽取8只新生大鼠取脑，以矢状缝为标志分为左右半脑，右侧脑用酶联免疫吸附试验（ELISA）检测脑组织EPO-R蛋白水平，左侧脑用反转录聚合酶链式反应（RT-PCR）检测EPO-R mRNA水平。结果（1）随大鼠成熟度的增加，正常对照组大鼠脑EPO-R蛋白（P2：13.73±2.04、P7：11.01±3.36、P12：10.52±2.35）及EPO-R mRNA（P2：0.44±0.05、P7：0.39±0.03、P12：0.38±0.04）表达下调，P2时表达水平与P7比较，差异有显著性（P<0.05），而P7与P12比较，差异无显著性（P>0.05）；（2）LPS组EPO-R蛋白与EPO-R mRNA表达较正常对照组上调，7日龄时正常对照组与LPS组比较，差异有显著性（P<0.05），而12日龄时两组差异无显著性（P>0.05）。结论随大鼠成熟度增加，脑组织EPO-R表达下调；LPS可上调大鼠脑组织EPO-R表达。%ObjectiveTo investigate the Erythropoietin Receptor(EPO-R) expression of rat brain at different developmental maturity and the effects of infection on EPO-R expression.Method Postnatal day 2 (P2) newborn SD rats were randomly divided into 2 groups:Control group(equal volume of saline) and Lipopolysaccharide (LPS) group[0.6 mg/(kg·d) LPS].The newborn rats in each group were administered corresponding drugs respectively at the corresponding time by intraperitoneal injection for 5 consecutive days,and continued to raise until P12. Every 8 newborn rats in A groups on P2,P7 and P12 and B group on P7 and P12 were selected randomly , the brains was divided into left and right hemispheres marked by sagittal suture.ELISA method were adopted to evaluate Erythropoietin Receptor (EPOR) portein level of the right cerebral hemisphere and RT-PCR method to investigate EPOR mRNA level of the left cerebral hemisphere. Result With the increased maturity of rats, normal rats brain EPO-R protein (P2:13.73±2.04 、P7:11.01±3.36、P12:10.52±2.35) and EPO-R mRNA (P2: 0.44 ± 0.05, P7: 0.39 ± 0.03, P12: 0.38 ± 0.04) were down-regulated, there was a significant difference between P2 and P7 expression levels (P<0.05), while differences between P7 and P12 showed no significant (P> 0.05). EPO-R protein and EPO-R mRNA expression in LPS group were up-regulated compared with normal group, but the difference was statistically significant at P7 (P<0.05), but not at P12 (P> 0.05).ConclusionThese data suggest that EPO-R expression level has a tendency to decline with the increase of brain development and EPO-R was dramatically up regulated after LPS infection in neonatal rat brain.