摘要
目的观察siRNA沉默脑组织血管内皮生长因子（VEGF）表达后对高原大鼠血脑屏障通透性的影响，探讨高原脑水肿的病理机制和预防方法。方法50只Wistar大鼠随机分人正常对照组（NC）、高原对照组（HC）、脑室生理盐水对照组（SC）、siRNA静脉干预组（IVI）和siRNA脑室干预组（CVI）。建立高原大鼠模型；NC组大鼠正常饲养；HC组大鼠造模前给予尾静脉内注射生理盐水；SC组在造模前给予脑室注射生理盐水；IVI组在造模前给予尾静脉注射VEGF特异性siRNA，CVI组给予脑室内注射VEGF特异性siRNA。造模24h后迅速断头取前脑，干湿重法测定脑组织含水百分率及应用荧光素钠透过率测定血脑屏障通透性；实时荧光定量RT-PCR检测VEGF-mRNA表达，Western印迹法测定大鼠脑组织VEGF表达。结果HC组脑组织VEGF-mRNA、VEGF表达及NaFl含量均显著高于NC组[VEGF-mRNA从（21．6±3．5）Kcopies／μg上升到（36．3±3．9）Kcopies／μg，VEGF从0．48±0．09增加到0．77±0．12，NaF1含量从（548-4-48）rfu／mg增加到（674±32）rfu／mg，均P〈0．01]。与HC组相比，IVI组脑组织VEGFmRNA、VEGF表达及NaF1含量差异无统计学意义（均P〉0．05）。CVI组脑组织VEGF—mRNA、VEGF表达及NaF1显著低于HC组[VEGF-mRNA从（36．3±3．9）Kcopies／μg降低到（19．9±4．3）Kcopies／μg，P〈0．0l；VEGF从0．77±0．12降低到0．44±0．13，P〈0．01；NaF1含量从（674±32）rfu／mg下降到（542±77）rfu／mg，P〈0．05]。各组间脑组织含水率差异无统计学意义（P〉0．05）。结论高原低氧诱发的VEGF表达增高是高原脑水肿的重要病理环节，脑室内应用特异性沉默VEGF的siRNA可阻断VEGF的表达，抑制毛细血管通透性增高，可成为预防高原脑水肿的新途径。
Objective To observe the change of expression of vascular endothelial growth factor （VEGF） and vascular leakage in the brain of rats exposed to high altitude with siRNA targeting vascular endothelial growth factor and explore the pathological mechanism and preventive approach of high altitude cerebral edema （HACE）. Methods Fifty male Wistar rats were divided randomly into normal control group （Ncon）, high altitude control group （Hcon）, intraventricular normal saline control group （Scon）, intraventricular siRNA group （CVI） and intravenous siRNA group （IVI）. Rats in Ncon were raised normally. Rats in Hcon, Scon, CVI and IVI pretreated with intravenous injection of normal saline, intraventricular injection of normal saline, intraventricular injection of siRNA and intravenous injection of siRNA respectively were exposed to a low-pressure cabin mimicking a high altitude of 7000 m for 24 h. The ratio of dry and wet brain weight was calculated and the sodium fluorescein leakage calculated to evaluate the cerebral edema and the blood brain barrier permeability. Also the real-time quantitative RT-PCR was employed to detect the expression of VEGF mRNA and the Western blot the expression of VEGF. Results Compared with rats in NC, high altitude exposure led to a significant increase in the levels of VEGF mRNA （ from 21.6±3.5 Keopies/μg to 36. 3± 3.9 Kcopies/μg, P 〈 0. 01 ） and protein （ from 48 ±0. 09 to 0.77 ±0. 12, P 〈 0. 01 ） in rat brain and fluorescence intensity of sodium fluorescein increased significantly （ from 548 ±48 rfu/mg to 674 ± 32 rfu/mg,P 〈 0. 01 ）. Intravenous injection of siRNA targeting to VEGF caused no significant change of expression VEGF mRNA and protein and fluorescence intensity of sodium fluoreseein in rat brain（ P 〉 0. 05, respectively）. While compared with rats in HC, intraventrieular injection of siRNA targeting to VEGF caused the significant reduction of expression of VEGF mRNA （ from 36. 3 ±3.9 to 19.9 ± 4. 3 ,P 〈 0. 01 ）and p
出处
《中华医学杂志》
CAS
CSCD
北大核心
2009年第37期2639-2643,共5页
National Medical Journal of China
基金
第三军医大学校中青年基金（2003D090）
关键词
SIRNA
血脑屏障
高原脑水肿
血管内皮生长因子
siRNA
Blood Brain Barrier
High altitude cerebral edema
Vascular endothelial growth factor
