摘要
体外合成红细胞生成素(Epo)3'-端增强子野生型及突变型片段,借助脂质体转入培养的大鼠肺微血管内皮细胞,用半定量RT-PCR方法测定内皮生长因子(VEGF)mRNA。结果发现:①内皮细胞在常氧下培养有VEGF基因转录,mRNA量吸光度(A)值为2.32±0.36;②缺氧4h时VEGF基因转录增加,mRNA量(A)值为4.71±0.52,与常氧组比较P<O.05;③野生型Epo 3'-端增强子片段能阻断缺氧对VEGF基因转录的诱导作用,mRNA量(A)值为2.29±0.41,与缺氧组比较P<0.05;而突变片段则无此作用,VEGF mRNA量(A)值为4.57±0.57,与缺氧组比较P>O.05。结果提示:在VEGF基因序列中可能存在Epo 3'-端增强子片段,它参与了内皮细胞的缺氧反应。
Wild and mutant erythropoietin (Epo) 3'-enhancer fragments were synthesized in vitro and transfected into cultured endothelial cells (ECs) of pulmonary microvessels in rats. Total RNA was extracted from ECs exposed to normoxia or hypoxia for 4 h. The amount of vascular endothelial growth factor (VEGF) mRNA was measured by semiquantitative RT-PCR. The results showed that ; (1) The transcription of VEGF gene was found in rat pulmonary microvascular ECs cultured in normoxia. The absorbance (A) of VEGF mRNA expressed was 2. 32?. 36; (2) VEGF gene transcription was increased in hypoxic ECs with a VEGF mRNA (A) of 4. 71 ?. 52 (P<0. 05 as compared with normoxia); (3) The wild Epo 3'-enhancer frag-ment could inhibit the hypoxia-induced exprssion of VEGF mRNA, the (A) of which was 2. 29?. 41 (P<. 0. 05 compared with hypoxia). Whereas the mutant sequence for wild Epo 3'-enhancer fragment couldn't in-hibit the hypoxia-induced VEGF mRNA expression, and the VEGF mRNA (A) being (4. 57?. 57) was kept in a high level (P>0. 05 compared with hypoxia group). These suggest that an Epo 3'-enhancer-like se-quence might be involved in VEGF gene, which may contribute to the hypoxic responses of ECs.
出处
《同济医科大学学报》
CSCD
1998年第5期333-335,344,共4页
Acta Universitatis Medicinae Tongji
基金
国家自然科学基金资助项目(No.39570277)
关键词
红细胞生成素
缺氧
血管内皮
生长因子
基因转录
erythropoietin
enhancer elements
hypoxia
vascular endothelial growth factor
