低氧诱导的人肺泡Ⅱ型上皮细胞SDF1表达与HIF1及HIF2的关系研究-内科学(消化内科)专业论文.docx

华 华 中 科 技 大 学 硕 士 学 位 论 文 PAGE 2 PAGE 2 SDF1 时可能起着协同作用。这一发现为将来阐明在 IPF 发病过程中肥大的 ATⅡAECs 高表达 SDF1 相关机制及如何募集血液循环中的 fibrocytes 运动至受损部位参与肺纤维 化的发生发展提供研究基础。这些也为 HIFs/SDF1 在 IPF 发病过程中的重要地位及其 作为治疗靶点的提供一个新的依据。 关键词：低氧；A549 细胞；SDF1；HIF；IPF Abstract The relationship between SDF1 expression upregulated in the human typeⅡ alveolar epithelium by hypoxia and HIF1 or HIF2. Objective: To study the expression of the chemonkine SDF1 in the ATⅡAECs(A549 cells) in normal and hypoxia condition,also to clarify whether SDF1 is regulated by HIF1,or HIF2 or the both. Methods: A549 cells were cultured under hypoxic (1.5%O2 concentration )or normal conditions for 48 hours ,and then realtime RT-PCR was used to determine the mRNA expression of SDF1, HIF1α and HIF2α in the two groups.Next,the siHIF1α,siHIF2α and scrambled control also negative control were transferred into the A549 cells with lip2000 for 48 hours all under hypoxic condition .Also the mRNA expresssion for three genes above was qaulitified by realtime RT-PCR in all the groups. Whole cell extracts were separated by 10% SDSand transferred to PVDF membrane. Immunoblotting was performed using HIF-1α, HIF-2α and beta-actin antibodies.At the same, SDF1 protein levels in culture media were measured using a commercial elisa kit. Results: The mRNA expression of HIF1α and HIF2α could be detected and the SDF1 was almost misssing under normal condition ;in contrast,the levels of the three were markedly upregualted under the hypoxic contidion for 48 hours（p﹤0.05）. The mRNA levels of HIF1α and SDF1 were decreased in the siHIF1α group and the levels of HIF2α and SDF1 declined in the siHIF1α group in contrast with the scrambled control .And the difference has statistical significance.It was demonstrated that the siRNA sequences were effective. Conclusion: Hypoxia could upregulate SDF1 in the Human lung adenocrcinoma cells A549 derived from ATⅡ AECs and may be mediated by HIF1 and HIF2,in which there was a cooperation between the two trans