人重组促红细胞生成素对早产儿脑室周围白质损伤模型鼠脑血管生成的影响

Recombinant human erythropoietin promotes angiogenesis in preterm rat models with periventricular white matter damage

目的探讨人重组促红细胞生成素（rh—EPO）在早产鼠脑室周围白质损伤模型鼠脑白质中的促血管新生作用。方法选取出生3日龄SD大鼠，随机数字表法分为假手术（Sham）组，缺氧缺血（HI）组和EPO治疗组。HI组和EPO治疗组幼鼠结扎右侧颈总动脉并吸入60mL／L的氮氧混合气体4h，Sham组幼鼠仅游离右侧颈总动脉。EPO治疗组术后即经腹腔给予大剂量rh—EPO（5U／g）1次，Sham组和HI组给予等量的9g／L盐水。采用免疫组织化学、Westernblot和实时荧光定量PCR（qRT—PCR）方法检测术后48h及96h大鼠脑白质中微血管密度（MVD）、CD34蛋白、动静脉标志物（ephrinB2和EphB4）表达情况。结果术后48h，HI组CD34蛋白（0．54±0．05）较Sham组（0．42±0．05）增加（P〈0．05），但HI组MVD、ephrinB2和EphB4与Sham组比较表达未见明显改变（P〉0．05）；EPO治疗组CD34蛋白（0．74±0．07）、ephrinB2（2．07±0．58）和EphB4（2．13±0．44）表达则较HI组（CD34蛋白：0.54±0．05，ephrinB2：0．70±0．23，EphB4：0．67±0．07）均明显增加（P均〈0．05），但是MVD未见明显增多（P〉0．05）。术后96h，HI组CD34蛋白（0．85±0．06）、MVD（3．14±1．21）、ephrinB2（7．51±1．89）和EphB4（4．58±0．82）较Sham组（CD34蛋白：0．62±0．06，MVD：1．50±1．04，ephrinB2：1．28±0．24，EphB4：1．21±0．22）均明显增多（P〈0．05）；EPO治疗组CD34蛋白（0．98±0．07）与MVD（4．71±1．38）表达较HI组（CD34蛋白：0．85±0．06，MVD：3．14±1．21）增多（P〈0．05），但ephrinB2和EphB4表达未见增多。结论未成熟鼠脑HI损伤后出现了内源性的血管新生反应，且rh—EPO可进一步促进该反应。

Objective To evaluate whether recombinant human erythropoietin （rh - EPO）could increase the angiogenie responses in preterm rat models with periventrieular white matter damage （PWMD）. Methods Three - day postnatal rats were divided into 3 groups randomly ： the sham group, the hypoxic - isehemie （HI） group and the recombi- nant human erythropoietin （rh -EPO）treatment group. Rat pups underwent permanent ligation of the right common ca- rotid artery followed by 60 mL/L 02 for 4 h or sham operation and normoxic exposure. Immediately after the HI, rats re- ceived a single intraperitoneal injection of rh -EPO （5 U/g）or saline. Angiogenesis -related cells （CD34 ＋ cells） , mi- crovessel density （MVD） and arteriovenous related genes （ ephrinB2 and EphB4） were examined at 48 h and 96 h after operation. Results At 48 h after operation,the proteins of CD34 in HI rats increased compared with the sham rats （ HI group vs Sham group ：0.54 ±0. 05 vs 0. 42± 0.05 ,P 〈 0.05 ）. However, the MVD, the mRNA of ephrinB2 and EphB4 did not change （P 〉 0.05 ）. The proteins of CD34, the mRNA of ephrinB2 and EphtM increased after rh - EPO treatment compared with HI rats. However, the MVD did not increase. As the proteins of CD34 increased further at 96 h after operation（ HI group vs Sham group：0.85 ±0.06 vs 0. 62 ±0.06 ,P 〈0.05） ,the MVD（3.14 ± 1.21 vs 1.50±1.04）, ephrinB2 （7.51 ±1.89 vs 1.28 ± 0.24） and EphB4 （4.58 ± 0.82 vs 1.21 ± 0.22） also increased （ all P 〈 0. 05 ）. And the proteins of CD34 increased after administration of rh- EPO（ EPO group vs HI group：0.98 ± 0.07 vs 0. 85±0. 06, P 〈 0.05 ） and MVD（ EPO group vs HI group ：4.71 ±1.38 vs 3.14 ± 1.21 ,P 〈 0.05 ） were increased after administra- tion of rh - EPO. However, the ephrinB2 and EphB2 did not increased after administration of rh - EPO at 96h time point. Conclusion Endogenous regenerative response is triggered in the damaged tissues and rh - EPO increases the angiogenesis in model rats with PWMD.