5/6肾切除大鼠低氧诱导因子1α和2α在肾内的表达和定位  

Expression and location of hypoxia inducible factor-1α and -2α in the remnant kidney of 5/6 nephrectomy rats

作　　者：俞小芳[1] 丁小强[1] 朱加明[1] 方艺[1] 邹建洲[1] 许讯辉[1] 蒋素华[1] 

机构地区：[1]复旦大学上海医学院附属中山医院肾病科,上海200032

出　　处：《中华肾脏病杂志》2010年第9期689-695,共7页Chinese Journal of Nephrology

基　　金：国家自然科学基金（30871176）;上海市科委基础处重点项目（07JC14007）;教育部211工程专项资金（第3期）

摘　　要：目的 探讨慢性肾脏病（CKD）进程中低氧诱导因子（HIF）的肾内表达部位和动态表达变化.方法 雄性SD大鼠行5/6肾切除后,分别于术后第1、2、4、6、8和12周处死大鼠.采集血、尿和肾组织标本,PAS染色观察残肾病理改变;连续切片免疫组化染色观察HIF-1α、HIF-2α在肾脏中的表达部位;Western印迹检测二者的蛋白表达变化;RT-PCR检测靶基因血管内皮生长因子（VEGF）、血红素加氧酶1（HO-1）的mRNA水平变化.结果 （1）大鼠5/6肾切除后第1周出现了短暂的急性肾衰竭[Scr（122.8±22.1）μmol/L],之后Scr下降并进入稳定的慢性肾衰竭阶段[（66.0±3.7）～（66.4±8.4）μmol/L],第6周后Scr进行性升高,残肾皮质出现进行性间质纤维化病变.（2）在肾切除早期阶段（术后第1周末）,HIF-1α和HIF-2α表达即开始增加,其中HIF-1α仅在萎缩扩张的肾小管上皮细胞表达,HIF-2α则表达于血管内皮细胞、间质成纤维细胞和小动脉的平滑肌细胞;至第4和6周,两者表达到达峰值;此后,伴随Scr升高和病理损伤加重,两者表达逐渐下降.（3）HIF靶基因VEGF、HO-1的mRNA在第4和第6周时呈暂时性的高表达.结论 CKD早期肾脏皮质HIF蛋白高表达和靶基因转录增加可能是对肾内缺氧的代偿性反应;CKD终末期HIF表达进行性减少,其在CKD进展中的作用值得进一步研究.Objective To investigate the location and expression of hypoxia inducible factor （HIF） subunits in the remnant kidney of 5/6 nephrectomy rats. Methods Remnant kidneys were produced in adult male SD rats by 5/6 nephrectomy. The renal function and histopathological changes were evaluated at week 1, 2, 4, 6, 8 and 12 after operation. Tissues of remnant kidneys were collected to detect the location and expression of HIF-1α and HIF-2α by immunohistochemistry staining and Western blotting. The mRNA levels of HIF targeted genes vascular endothelial growth factor （VEGF） and heme oxygenase-1 （HO-1） were determined by RTPCR. Results （1） 5/6 nephrectomy rats underwent one week of acute renal failure at first[Scr （122.8±22.1） μmol/L] and then developed compensative chronic renal failure [（66.0±3.7）-（66.4±8.4） μmol/L], but the level of Scr increased quickly after week 6 [（66.4±8.4）-（127.8±22.7） μmol/L],concomitantly with progressive tubulointerstitial fibrosis in remnant kidney cortex. （2） In cortex, HIF-1α was expressed only in the atrophic and dilated tubular cells while HIF-2α was located in endothelial, interstitial fibroblasts, and vascular smooth muscle cells. The semiquantitative results of imunohistochemistry and Western blotting revealed that HIF-1α and HIF-2α were both gradually up-regulated during the early stage of remnant kidney, peaked at week 4 and 6, and then gradually down-regulated. （3） The mRNA levels of HIF targeted genes VEGF and HO-1 transiently peeked at week 4 and 6, and then decreased gradually. Conclusions The increased stabilization of HIF-αprotein and transcription of HIF targeted genes at the early stage of this model is a compensation reaction towards hypoxia. The mechanism of decreased expression of HIF-α at the end stage of chronic kidney disease deserves further investigation.

关 键 词：肾切除术 肾脏病 慢性 缺氧诱导因子1 Α亚基 缺氧诱导因子2 α亚基 

分 类 号：R692[医药卫生—泌尿科学]