摘要
目的 观察急性低氧和低氧习服影响人HepG2细胞内红细胞生成素 (EPO) ,低氧诱导因子 1α(HIF 1α)和肝细胞核因子 4(HNF 4)基因表达。方法 HepG2细胞在 1%O2 下培养 2 4h后 ,2 1%O2 下培养 2 4h ,以此为 1个周期 ,连续低氧训练 6个周期 ,细胞达到低氧习服状态后 ,用Northern杂交方法检测EPO、HIF 1α和HNF 4基因表达。结果 HepG2细胞在急性低氧条件下培养48h后 ,胞内EPO、HIF 1α和HNF 4基因表达升高 ,mRNA含量分别升至常氧对照细胞的 4.3、2 .3、1.2倍 ;在低氧训练过程中 ,HepG2细胞内EPO、HIF 1α和HNF 4基因的mRNA含量逐渐下降 ;细胞达到低氧习服后 ,再急性低氧 48h ,EPO基因表达水平接近常氧对照组 ,HIF 1α和HNF 4的mRNA含量分别为常氧对照组的 81.4%和 12 2 .4%。结论 HepG2细胞达到低氧习服后 ,急性低氧对EPO基因表达的诱导作用减弱甚至受到抑制。与HNF 4相比 ,HIF 1α在急性低氧或低氧习服影响EPO基因表达中起着更为重要的作用。
ObjectiveTo observe the effect of acute hypoxia and hypoxic acclimatization on gene expression of erythropoietin (EPO) and its two transcriptional regulatory factors,hypoxia-inducible factor-1α (HIF-1α) and hepatic nuclear factor-4 (HNF-4),in HepG2 cells underlying its possibly biological significance.MethodsHuman HepG2 cells were cultured in 1% O_2 for 24 h,then in 21% O_2 for another 24 h which comprised a hypoxic training cycle.After 6 cycles,HepG2 cells came to the status of hypoxic acclimatization.Before and after hypoxic acclimatization,gene expression of EPO,HIF-1α and HNF-4 was detected by using Northern blot method.ResultsAcute hypoxia for 48 h could induce EPO,HIF-1α and HNF-4 gene expression in HepG2 cells significantly.In the course of hypoxic training,the gene expression of EPO,HIF-1α and HNF-4 was all decreased progressively.When HepG2 cells reached the hypoxic acclimatization status,the level of EPO gene expression in cells cultured in 1% O_2 for another 48 h was resumed to that in control cells.After hypoxic acclimatization,the change patterns of gene transcription of HIF-1α and HNF-4 were similar to that of EPO,but the change of HNF-4 expression was less sensitive to different hypoxia treatments in comparison with HIF-1α.ConclusionWhen the status of hypoxic acclimatization was reached,the hypoxia-induced increment of EPO gene transcription in HepG2 cells was inhibited,in which HIF-1αmight play a more important role than HNF-4.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2004年第4期417-419,共3页
Chinese Journal of Experimental Surgery
基金
国家自然科学基金重点资助项目 (39730 1 90 )
