摘要
目的观察外源性促红细胞生成素(EPO)对高体积分数氧(高氧)肺损伤中单核细胞趋化蛋白-1(MCP-1)表达的影响,探讨外源性EPO对高氧肺损伤的干预作用。方法将96只出生12h内新生大鼠随机分为4组。Ⅰ组:空气对照;Ⅱ组:空气+重组人促红细胞生成素(rhEPO);Ⅲ组:高氧对照;Ⅳ组:高氧+rhEPO。Ⅲ组、Ⅳ组新生大鼠高氧暴露(吸氧体积分数850mL·L-1),Ⅱ组、Ⅳ组于出生0d和2d予rhEPO1200IU·kg-1背部皮下注射,Ⅰ组、Ⅲ组予等量9g·L-1盐水注射。在实验3d、7d和14d每组随机选取8只处死,取其肺组织,采用HE染色观察其肺组织病理改变,生化法检测其肺组织髓过氧化物酶(MPO)水平;免疫组织化学和Western blotting法检测其肺组织MCP-1蛋白的变化。结果Ⅲ组新生大鼠出生3d时肺组织可见炎症反应,7d时最为显著,14d时肺泡结构简化,间质呈不同程度纤维化。Ⅳ组新生大鼠出生7d时炎性渗出和浸润较Ⅲ组减轻,14d时肺泡发育改善。Ⅳ组各时点MPO水平较Ⅲ组明显降低[(0.58±0.06)U·L-1vs(0.68±0.08)U·L-1,P<0.05;(0.77±0.06)U·L-1vs(1.09±0.14)U·L-1,P<0.001;(0.66±0.43)U·L-1vs(0.74±0.05)U·L-1,P<0.05]。MCP-1在Ⅲ组表达增强,7d时达峰值(P<0.001);Ⅳ组MCP-1表达较Ⅲ组减弱[(21.64±3.65)vs(28.98±3.66),P<0.01;(41.41±6.21)vs(95.69±6.96),P<0.001;(30.21±3.48)vs(43.98±5.29),P<0.001]。Ⅰ组、Ⅲ组、Ⅳ组各时点MCP-1蛋白变化与肺组织MPO水平呈正相关(r=0.538,P<0.01;r=0.906,P<0.001;r=0.800,P<0.001)。结论EPO可减轻高氧导致的肺组织炎性损伤,最终改善肺发育,EPO抗炎作用机制与其抑制趋化因子MCP-1表达有关。
Objective To observe the effect of erythropoietin（EPO） on monocyte chemoattractant protein-1（MCP-1） in hyperoxia-induced lung injury and explore the intervention effect of EPO on hyperoxia-induced lung injury in newborn rats.Methods Ninety-six Wistar rat pups were pooled together within 12 hours after birth and randomly divided into 4 groups：group Ⅰ was air-exposed and control group;group Ⅱ was air-exposed and human recombinant erythropoietin （rhEPO）-treated group;group Ⅲ was hyperoxia-exposed placebo group,and group Ⅳ was hyperoxia-exposed and rhEPO-treated group.Rats in group Ⅰ and group Ⅱ were kept in standard cage with mother at room air.The rats in group Ⅲ and group Ⅳ were kept in standard cage with mother within an oxygen chamber into which oxygen was continuously delivered [fraction of inspired oxygen（FiO2）=850 mL·L-1].The rats in group Ⅱ and group Ⅳ received rhEPO （1 200 IU·kg-1） subcutaneously on postnatal day 0 and day 2.The rats in group Ⅰ and group Ⅲ received 9 g·L-1 saline in the same way.Eight rat pups from each group were randomly chosen and then killed on postnatal day 3 ,day 7,and day 14.The pulmonary histological and morphometric changes were observed by hematoxylin-eosin （HE） staining under light microscope.Myeloperoxidase （MPO） activity in lung tissue was assessed by biochemistry assay.Changes of MCP-1 in lung tissue were measured by immunohistochemistry and Western blotting.Results In group Ⅲ,there were a few inflammatory cells infiltrating in interstitial on postnatal day 3 and inflammatory response worsened on day 7,on day 14,alveolar number became less and terminal air space became even much larger in group Ⅲ compared with that in group Ⅰ,and interstitial fibrosis were evident.With rhEPO treatment,the morphometric abnormalities induced by hyperoxia were ameliorated greatly.Content of MPO in lungs increased in group Ⅲ on day 3,and reached peak on day 7 compared with that in group Ⅰ,and it significantly decreased in group Ⅳ compared with that in group Ⅲ [（0.58±0.06） U·L-1 vs （0.68±0.08） U·L-1,P〈0.05;（0.77±0.06） U·L-1 vs （1.09±0.14） U·L-1,P〈0.001;（0.66±0.43） U·L-1 vs （0.74±0.05） U·L-1,P〈0.05].Expressions of MCP-1 were much higher on day 7 in group Ⅲ（P〈0.001） compared with that in the other groups,but were relieved significantly with rhEPO treatment[（21.64±3.65） vs （28.98±3.66）,P〈0.01;（41.41±6.21） vs （95.69±6.96）,P〈0.001;（30.21±3.48） vs （43.98±5.29）,P〈0.001].The changes of MCP-1 were positively related with the changes of MPO in lungs covering group Ⅰ,group Ⅲ and group Ⅳ on day 3,day 7 and day 14,respectively（r=0.538,P〈0.01;r=0.906,P〈0.001;r=0.800,P〈0.001）.Conclusions EPO can significantly attenuate the hyperoxia-induced inflammatory response in newborn rat lungs.The anti-inflammatory effect of EPO on hyperoxic lung injury may be mediated by the down-modulation of MCP-1 protein.
出处
《实用儿科临床杂志》
CAS
CSCD
北大核心
2010年第2期92-95,共4页
Journal of Applied Clinical Pediatrics
基金
国家自然科学基金(30672253)
